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Sample records for activity limitation due

  1. Massive spalling of intermetallic compounds in solder-substrate reactions due to limited supply of the active element

    SciTech Connect

    Yang, S. C.; Ho, C. E.; Chang, C. W.; Kao, C. R.

    2007-04-15

    Massive spalling of intermetallic compounds has been reported in the literature for several solder/substrate systems, including SnAgCu soldered on Ni substrate, SnZn on Cu, high-Pb PbSn on Cu, and high-Pb PbSn on Ni. In this work, a unified thermodynamic argument is proposed to explain this rather unusual phenomenon. According to this argument, two necessary conditions must be met. The number one condition is that at least one of the reactive constituents of the solder must be present in a limited amount, and the second condition is that the soldering reaction has to be very sensitive to its concentration. With the growth of intermetallic, more and more atoms of this constituent are extracted out of the solder and incorporated into the intermetallic. As the concentration of this constituent decreases, the original intermetallic at the interface becomes a nonequilibrium phase, and the spalling of the original intermetallic occurs.

  2. Task Failure during Exercise to Exhaustion in Normoxia and Hypoxia Is Due to Reduced Muscle Activation Caused by Central Mechanisms While Muscle Metaboreflex Does Not Limit Performance.

    PubMed

    Torres-Peralta, Rafael; Morales-Alamo, David; González-Izal, Miriam; Losa-Reyna, José; Pérez-Suárez, Ismael; Izquierdo, Mikel; Calbet, José A L

    2015-01-01

    To determine whether task failure during incremental exercise to exhaustion (IE) is principally due to reduced neural drive and increased metaboreflex activation eleven men (22 ± 2 years) performed a 10 s control isokinetic sprint (IS; 80 rpm) after a short warm-up. This was immediately followed by an IE in normoxia (Nx, PIO2:143 mmHg) and hypoxia (Hyp, PIO2:73 mmHg) in random order, separated by a 120 min resting period. At exhaustion, the circulation of both legs was occluded instantaneously (300 mmHg) during 10 or 60 s to impede recovery and increase metaboreflex activation. This was immediately followed by an IS with open circulation. Electromyographic recordings were obtained from the vastus medialis and lateralis. Muscle biopsies and blood gases were obtained in separate experiments. During the last 10 s of the IE, pulmonary ventilation, VO2, power output and muscle activation were lower in hypoxia than in normoxia, while pedaling rate was similar. Compared to the control sprint, performance (IS-Wpeak) was reduced to a greater extent after the IE-Nx (11% lower P < 0.05) than IE-Hyp. The root mean square (EMGRMS) was reduced by 38 and 27% during IS performed after IE-Nx and IE-Hyp, respectively (Nx vs. Hyp: P < 0.05). Post-ischemia IS-EMGRMS values were higher than during the last 10 s of IE. Sprint exercise mean (IS-MPF) and median (IS-MdPF) power frequencies, and burst duration, were more reduced after IE-Nx than IE-Hyp (P < 0.05). Despite increased muscle lactate accumulation, acidification, and metaboreflex activation from 10 to 60 s of ischemia, IS-Wmean (+23%) and burst duration (+10%) increased, while IS-EMGRMS decreased (-24%, P < 0.05), with IS-MPF and IS-MdPF remaining unchanged. In conclusion, close to task failure, muscle activation is lower in hypoxia than in normoxia. Task failure is predominantly caused by central mechanisms, which recover to great extent within 1 min even when the legs remain ischemic. There is dissociation between the

  3. Task Failure during Exercise to Exhaustion in Normoxia and Hypoxia Is Due to Reduced Muscle Activation Caused by Central Mechanisms While Muscle Metaboreflex Does Not Limit Performance

    PubMed Central

    Torres-Peralta, Rafael; Morales-Alamo, David; González-Izal, Miriam; Losa-Reyna, José; Pérez-Suárez, Ismael; Izquierdo, Mikel; Calbet, José A. L.

    2016-01-01

    To determine whether task failure during incremental exercise to exhaustion (IE) is principally due to reduced neural drive and increased metaboreflex activation eleven men (22 ± 2 years) performed a 10 s control isokinetic sprint (IS; 80 rpm) after a short warm-up. This was immediately followed by an IE in normoxia (Nx, PIO2:143 mmHg) and hypoxia (Hyp, PIO2:73 mmHg) in random order, separated by a 120 min resting period. At exhaustion, the circulation of both legs was occluded instantaneously (300 mmHg) during 10 or 60 s to impede recovery and increase metaboreflex activation. This was immediately followed by an IS with open circulation. Electromyographic recordings were obtained from the vastus medialis and lateralis. Muscle biopsies and blood gases were obtained in separate experiments. During the last 10 s of the IE, pulmonary ventilation, VO2, power output and muscle activation were lower in hypoxia than in normoxia, while pedaling rate was similar. Compared to the control sprint, performance (IS-Wpeak) was reduced to a greater extent after the IE-Nx (11% lower P < 0.05) than IE-Hyp. The root mean square (EMGRMS) was reduced by 38 and 27% during IS performed after IE-Nx and IE-Hyp, respectively (Nx vs. Hyp: P < 0.05). Post-ischemia IS-EMGRMS values were higher than during the last 10 s of IE. Sprint exercise mean (IS-MPF) and median (IS-MdPF) power frequencies, and burst duration, were more reduced after IE-Nx than IE-Hyp (P < 0.05). Despite increased muscle lactate accumulation, acidification, and metaboreflex activation from 10 to 60 s of ischemia, IS-Wmean (+23%) and burst duration (+10%) increased, while IS-EMGRMS decreased (−24%, P < 0.05), with IS-MPF and IS-MdPF remaining unchanged. In conclusion, close to task failure, muscle activation is lower in hypoxia than in normoxia. Task failure is predominantly caused by central mechanisms, which recover to great extent within 1 min even when the legs remain ischemic. There is dissociation between the

  4. Limitations in life participation and independence due to secondary conditions.

    PubMed

    Koritsas, Stella; Iacono, Teresa

    2009-11-01

    The effects of secondary conditions across adults with autism, Down syndrome, and cerebral palsy were explored in terms of overall limitation in life participation and independence, changes over time, and the degree and nature of limitation in specific secondary conditions. Information was obtained for 35 adults with autism, 49 with Down syndrome, and 29 with cerebral palsy (N = 113). Caregivers completed a questionnaire exploring secondary conditions on two occasions. Participants with cerebral palsy experienced the greatest overall limitations of the three groups. This finding is due to several secondary conditions. There were no changes in limitation scores over time. Implications related to health care for these groups are discussed.

  5. Functional limitations due to foot involvement in spondyloarthritis

    PubMed Central

    Ozaras, Nihal; Havan, Nuri; Poyraz, Emine; Rezvanı, Aylin; Aydın, Teoman

    2016-01-01

    [Purpose] Spondyloarthritis is a major inflammatory disease followed-up in the rheumatology clinics, foot involvement in spodyloarthritis is common. The functional states of patients with spondyloarthritis are usually evaluated globally. The aim of this study was to assess the foot involvement-related functional limitations in patients with spondyloarthritis. [Subjects and Methods] Patients with ankylosing spondylitis and psoriatic arthritis with foot pain more than 4 weeks who underwent anteroposterior and lateral feet radiography were enrolled into the study. A “clinical findings score” was calculated by assigning 1 point for every finding of swelling, redness, and tenderness. C-reactive protein and erythrocyte sedimentation rate were used as serum markers for disease activity. Foot radiograms were evaluated using the spondyloarthropathy tarsal radiographic index and the foot-related functional state of patients was determined by the Turkish version of the Foot and Ankle Outcome Score. [Results] There were no relationships between Foot and Ankle Outcome Score subscales and clinical findings score, serum markers, or radiologic score. Pain and symptoms subscale scores were result positively correlated with activity of daily living, sport and recreation, and quality of life subscale scores. [Conclusion] Pain and symptoms are the main determinants of foot-related functional limitations in spondyloarthritis. PMID:27512252

  6. Functional limitations due to foot involvement in spondyloarthritis.

    PubMed

    Ozaras, Nihal; Havan, Nuri; Poyraz, Emine; Rezvanı, Aylin; Aydın, Teoman

    2016-07-01

    [Purpose] Spondyloarthritis is a major inflammatory disease followed-up in the rheumatology clinics, foot involvement in spodyloarthritis is common. The functional states of patients with spondyloarthritis are usually evaluated globally. The aim of this study was to assess the foot involvement-related functional limitations in patients with spondyloarthritis. [Subjects and Methods] Patients with ankylosing spondylitis and psoriatic arthritis with foot pain more than 4 weeks who underwent anteroposterior and lateral feet radiography were enrolled into the study. A "clinical findings score" was calculated by assigning 1 point for every finding of swelling, redness, and tenderness. C-reactive protein and erythrocyte sedimentation rate were used as serum markers for disease activity. Foot radiograms were evaluated using the spondyloarthropathy tarsal radiographic index and the foot-related functional state of patients was determined by the Turkish version of the Foot and Ankle Outcome Score. [Results] There were no relationships between Foot and Ankle Outcome Score subscales and clinical findings score, serum markers, or radiologic score. Pain and symptoms subscale scores were result positively correlated with activity of daily living, sport and recreation, and quality of life subscale scores. [Conclusion] Pain and symptoms are the main determinants of foot-related functional limitations in spondyloarthritis. PMID:27512252

  7. Lunar laser ranging and limits due to the Earth's atmosphere

    NASA Astrophysics Data System (ADS)

    Currie, Douglas; Prochazka, Ivan

    2015-10-01

    The ultimate limits on high accuracy laser ranging to satellites from the ground appear to be caused by the effects of the earth's atmosphere. Other impediments in terms of lasers, timing equipment and calibration seem to be evolving to the point of providing very high accuracy. We shall address the role of the earth's atmosphere for lunar laser ranging. In the near future, the robotic deployment of next generation lunar laser retroreflectors is planned. With proper robotic deployment, these retroreflectors may support single photo-electron ranging accuracy at the 100 micron level or better. In particular, there are questions of the random and systematic delays and broadening of a very narrow laser pulse. Theoretical and experimental results will be discussed that address estimates of the magnitudes of these effects and the issue of precision vs. accuracy. These effects may be roughly divided into three domains: High frequency effects due to atmospheric turbulence, low frequency effects due to atmospheric "slopes" and atmospheric waves and tides and spectral dispersion of the narrow pulse. In conclusion, the route to better ranging through the earth's atmosphere appears to be more advance modeling of local meteorological effects, in a program that can be implemented at a reasonable cost.

  8. Communication Limits Due to Photon-Detector Jitter

    NASA Technical Reports Server (NTRS)

    Moision, Bruce E.; Farr, William H.

    2008-01-01

    A theoretical and experimental study was conducted of the limit imposed by photon-detector jitter on the capacity of a pulse-position-modulated optical communication system in which the receiver operates in a photon-counting (weak-signal) regime. Photon-detector jitter is a random delay between impingement of a photon and generation of an electrical pulse by the detector. In the study, jitter statistics were computed from jitter measurements made on several photon detectors. The probability density of jitter was mathematically modeled by use of a weighted sum of Gaussian functions. Parameters of the model were adjusted to fit histograms representing the measured-jitter statistics. Likelihoods of assigning detector-output pulses to correct pulse time slots in the presence of jitter were derived and used to compute channel capacities and corresponding losses due to jitter. It was found that the loss, expressed as the ratio between the signal power needed to achieve a specified capacity in the presence of jitter and that needed to obtain the same capacity in the absence of jitter, is well approximated as a quadratic function of the standard deviation of the jitter in units of pulse-time-slot duration.

  9. Limitations in Life Participation and Independence Due to Secondary Conditions

    ERIC Educational Resources Information Center

    Koritsas, Stella; Iacono, Teresa

    2009-01-01

    The effects of secondary conditions across adults with autism, Down syndrome, and cerebral palsy were explored in terms of overall limitation in life participation and independence, changes over time, and the degree and nature of limitation in specific secondary conditions. Information was obtained for 35 adults with autism, 49 with Down syndrome,…

  10. Limitations on Ku-band communications due to multipath

    NASA Technical Reports Server (NTRS)

    Lindsey, J. F.; Rudnicki, J. F.

    1977-01-01

    The earth and orbiter body reflections involving the Tracking Data Relay Satellite (TDRS)/orbiter communications link are evaluated. Recommendations address operational conditions in order to avoid critical multipath impacts, modulation preferences during acquisition, and preferred scan limit implementation.

  11. Solar irradiance variations due to active regions

    SciTech Connect

    Oster, L.; Schatten, K.H.; Sofia, S.

    1982-05-15

    We have been able to reproduce the variations of the solar irradiance observed by ACRIM to an accuracy of better than +- 0.4 W m/sup -2/, assuming that during the 6 month observation period in 1980 the solar luminosity was constant. The improvement over previous attempts is primarily due to the inclusion of faculae. The reproduction scheme uses simple geometrical data on spot and facula areas, and conventional parameters for the respective fluxes and angular dependencies. The quality of reproduction is not very sensitive to most of the details of these parameters; nevertheless, there conventional parameters cannot be very different from their actual values in the solar atmosphere. It is interesting that the time average of the integrated excess emission (over directions) of the faculae cancels out the integrated deficit produced by the spots, within an accuracy of about 10%. If this behavior were maintained over longer periods of time, say, on the order of an activity cycle, active regions could be viewed as a kind of lighthouse where the energy deficit near the normal direction, associated with the spots, is primarily reemitted close to the tangential directions by the faculae. The currently available data suggest that energy ''storage'' associated with the redirection of flux near active regions on the Sun is comparable to the lifetime of the faculae.

  12. An adaptability limit to climate change due to heat stress.

    PubMed

    Sherwood, Steven C; Huber, Matthew

    2010-05-25

    Despite the uncertainty in future climate-change impacts, it is often assumed that humans would be able to adapt to any possible warming. Here we argue that heat stress imposes a robust upper limit to such adaptation. Peak heat stress, quantified by the wet-bulb temperature T(W), is surprisingly similar across diverse climates today. T(W) never exceeds 31 degrees C. Any exceedence of 35 degrees C for extended periods should induce hyperthermia in humans and other mammals, as dissipation of metabolic heat becomes impossible. While this never happens now, it would begin to occur with global-mean warming of about 7 degrees C, calling the habitability of some regions into question. With 11-12 degrees C warming, such regions would spread to encompass the majority of the human population as currently distributed. Eventual warmings of 12 degrees C are possible from fossil fuel burning. One implication is that recent estimates of the costs of unmitigated climate change are too low unless the range of possible warming can somehow be narrowed. Heat stress also may help explain trends in the mammalian fossil record.

  13. SVE design: Mass transfer limitation due to molecular diffusion

    SciTech Connect

    Yang, Y.J.; Gates, T.M.; Edwards, S.

    1999-09-01

    Vaporization and soil adsorption are the two mass transfer mechanisms that control contaminant recovery rates for soil vapor extraction (SVE) systems. At most soil remediation sites, contaminants are distributed among three phases, namely, soil particles, pore water, and soil vapor. Contaminant mass transfer from adsorption sites into a convective vapor stream involves desorption, diffusion through pore water, and vaporization into soil vapor. An SVE design model is proposed to describe this three-phase mass transfer process and assist the design and evaluation of SVE systems. The model contains analytical solutions developed to estimate contaminant concentrations in the vapor phase and predict contaminant removal rates. Monitoring data from two full-scale SVE systems were used for model development and calibration. The results suggest that contaminant diffusion through the pore water is the rate-limiting step and leads to remediation inefficiency of an SVE system. Mass Transfer retardation from molecular diffusion in water is likely the major contributing component to the venting efficiency coefficient of Staudinger et al.

  14. 12 CFR 591.5 - Limitation on exercise of due-on-sale clauses.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 6 2013-01-01 2012-01-01 true Limitation on exercise of due-on-sale clauses... PREEMPTION OF STATE DUE-ON-SALE LAWS § 591.5 Limitation on exercise of due-on-sale clauses. (a) General... without regard to any limitations imposed by state law on either their inclusion or exercise...

  15. 12 CFR 591.5 - Limitation on exercise of due-on-sale clauses.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 5 2010-01-01 2010-01-01 false Limitation on exercise of due-on-sale clauses... PREEMPTION OF STATE DUE-ON-SALE LAWS § 591.5 Limitation on exercise of due-on-sale clauses. (a) General... without regard to any limitations imposed by state law on either their inclusion or exercise...

  16. 12 CFR 191.5 - Limitation on exercise of due-on-sale clauses.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 1 2014-01-01 2014-01-01 false Limitation on exercise of due-on-sale clauses... PREEMPTION OF STATE DUE-ON-SALE LAWS § 191.5 Limitation on exercise of due-on-sale clauses. (a) General... without regard to any limitations imposed by state law on either their inclusion or exercise...

  17. 12 CFR 591.5 - Limitation on exercise of due-on-sale clauses.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 5 2011-01-01 2011-01-01 false Limitation on exercise of due-on-sale clauses... PREEMPTION OF STATE DUE-ON-SALE LAWS § 591.5 Limitation on exercise of due-on-sale clauses. (a) General... without regard to any limitations imposed by state law on either their inclusion or exercise...

  18. 12 CFR 191.5 - Limitation on exercise of due-on-sale clauses.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 1 2012-01-01 2012-01-01 false Limitation on exercise of due-on-sale clauses... PREEMPTION OF STATE DUE-ON-SALE LAWS § 191.5 Limitation on exercise of due-on-sale clauses. (a) General... without regard to any limitations imposed by state law on either their inclusion or exercise...

  19. 12 CFR 591.5 - Limitation on exercise of due-on-sale clauses.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 6 2014-01-01 2012-01-01 true Limitation on exercise of due-on-sale clauses... PREEMPTION OF STATE DUE-ON-SALE LAWS § 591.5 Limitation on exercise of due-on-sale clauses. (a) General... without regard to any limitations imposed by state law on either their inclusion or exercise...

  20. 12 CFR 191.5 - Limitation on exercise of due-on-sale clauses.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Limitation on exercise of due-on-sale clauses... PREEMPTION OF STATE DUE-ON-SALE LAWS § 191.5 Limitation on exercise of due-on-sale clauses. (a) General... without regard to any limitations imposed by state law on either their inclusion or exercise...

  1. 12 CFR 591.5 - Limitation on exercise of due-on-sale clauses.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 6 2012-01-01 2012-01-01 false Limitation on exercise of due-on-sale clauses... PREEMPTION OF STATE DUE-ON-SALE LAWS § 591.5 Limitation on exercise of due-on-sale clauses. (a) General... without regard to any limitations imposed by state law on either their inclusion or exercise...

  2. Active inrush-current limiter

    NASA Technical Reports Server (NTRS)

    Kichak, R. A.

    1977-01-01

    By stretching turn-on time from approximately 1 to 200 ms, effects of inrush current (and of associated large current spikes) and current rate of rise (dl/dt) are made potentially less severe. Limiter arrangement consists of time-variable impedance connected in series between input dc power source return and power circuit of converter.

  3. When hospitals limit organizing activity.

    PubMed

    Gilmore, C B

    1988-01-01

    Since 1974, when the NLRA was extended to cover nonprofit medical institutions, hospitals have been faced with the challenge of accommodating their employees' right to engage in organizing and concerted activities while preventing such activities from disrupting patient care. Some hospitals have sought to protect the interests of patients by prohibiting solicitation and distribution in all areas to which patients and visitors have access. The Board and the courts have generally found such rules overly broad and violative of employee rights under the NLRA. In the following survey of cases involving solicitation/distribution rules, the author points out that the courts have consistently evaluated these rules on the basis of the special nature of the hospital setting. Accordingly, advises the author, hospital administrators who are promulgating distributions and solicitation rules covering a given location must consider the individual characteristics of that location, namely, its physical layout, the type of work performed there, and the availability of alternate space.

  4. Ionospheric Response Due to Seismic Activity

    NASA Astrophysics Data System (ADS)

    Sharma, Dinesh Kumar

    2016-07-01

    Signatures of the seismic activity in the ionospheric F2 region have been studied by analyzing the measurement of electron and ion temperatures during the occurrence of earthquake. The ionospheric electron and ion temperatures data recorded by the RPA payload aboard the Indian SROSS-C2 satellite during the period from January 1995 to December 2000 were used for the altitude range 430-630 km over Indian region. The normal day's electron and ion temperatures have been compared to the temperatures recorded during the seismic activity. The details of seismic events were obtained from USGS earthquake data information website. It has been found that the average electron temperature is enhanced during the occurrence of earthquakes by 1.2 to 1.5 times and this enhancement was for ion temperature ranging from 1.1to 1.3 times over the normal day's average temperatures. The above careful quantitative analysis of ionospheric electron and ion temperatures data shows the consistent enhancement in the ionospheric electron and ion temperatures. It is expected that the seismogenic vertical electrical field propagates up to the ionospheric heights and induces Joule heating that may cause the enhancement in ionospheric temperatures.

  5. Family caregivers and limitations in social activities.

    PubMed

    Miller, B; Montgomery, A

    1990-03-01

    Constriction of social and personal activities is one of the most frequently noted consequences of caring for a frail elder. This study analyzed the correlates of perceived limitations in social activities using data from a national sample of the frail elderly and their caregivers. Two research issues were addressed: 1) What differences in demographic, family, and caregiving attributes are associated with variation in perceived restricted social activities? and, 2) How does the process influencing restriction of social activities vary by family relationship of the caregiver? Higher levels of elder dependency and task demands were characteristic of those who reported social limitations, and daughters and wives were more likely to report such limitations than sons and husbands. Subjective assessment of time and task demands, however, were more important influences than objective caregiving activities for all family caregivers. PMID:2180010

  6. Family caregivers and limitations in social activities.

    PubMed

    Miller, B; Montgomery, A

    1990-03-01

    Constriction of social and personal activities is one of the most frequently noted consequences of caring for a frail elder. This study analyzed the correlates of perceived limitations in social activities using data from a national sample of the frail elderly and their caregivers. Two research issues were addressed: 1) What differences in demographic, family, and caregiving attributes are associated with variation in perceived restricted social activities? and, 2) How does the process influencing restriction of social activities vary by family relationship of the caregiver? Higher levels of elder dependency and task demands were characteristic of those who reported social limitations, and daughters and wives were more likely to report such limitations than sons and husbands. Subjective assessment of time and task demands, however, were more important influences than objective caregiving activities for all family caregivers.

  7. Analytic solution for the limiting shape of profiles due to fretting wear

    PubMed Central

    Popov, Valentin L.

    2014-01-01

    We consider fretting wear due to tangential oscillations of two contacting bodies. For small oscillation amplitudes, the wear occurs only in a circular slip zone at the border of the contact area. With increasing number of cycles, the wear profile tends to a limiting form, in which no further wear occurs. Under assumption of a constant coefficient of friction, the limiting form of the wear profile does not depend on the particular wear criterion and can be calculated analytically. An explicit analytic solution is presented for arbitrary initial shape and illustrated for the cases of parabolic and conical shapes. PMID:24434938

  8. Cholestatic hepatic injury due to a thyroid storm: a case report from a resource limited setting

    PubMed Central

    2012-01-01

    Introduction Thyroid storm is an endocrinological emergency caused by an exacerbation of the hyperthyroid state and is characterized by multi organ dysfunction. Liver dysfunction or injury predominantly of a cholestatic type is one of the atypical manifestations of thyroid storm and has been previously described in literature. However, there have been few published case reports among African patients and from resource limited settings. Case report We report a case of a 21 year old Ugandan female patient who presented with a thyroid storm due to untreated Graves’ disease complicated by cholestatic hepatic injury, congestive heart failure and acute kidney injury. Conclusion This case highlights the varied multi organ dysfunctions seen in a patient with thyroid storm with emphasis on liver injury mainly to increase awareness among clinicians in resource limited settings. Mechanisms of liver injury due to thyroid storm or hyperthyroidism are discussed in the literature review. PMID:22839423

  9. Resolution limitation in superconducting transition edge photon detectors due to downconversion phonon noise

    SciTech Connect

    Kozorezov, A. G.; Wigmore, J. K.; Martin, D.; Verhoeve, P.; Peacock, A.

    2006-11-27

    The authors have identified an important source of line broadening in transition edge sensors used as optical photon detectors. It arises through the loss of high energy phonons into the substrate during the initial photon energy downconversion stage. Because of the relatively small number of phonons involved, the loss rate is subjected to large fluctuations due to the statistical nature of the energy exchange processes. They show that the resulting noise may represent a significant limitation to the resolving power of current detectors.

  10. Elucidating the Performance Limitations of Lithium-ion Batteries due to Species and Charge Transport through Five Characteristic Parameters

    PubMed Central

    Jiang, Fangming; Peng, Peng

    2016-01-01

    Underutilization due to performance limitations imposed by species and charge transports is one of the key issues that persist with various lithium-ion batteries. To elucidate the relevant mechanisms, two groups of characteristic parameters were proposed. The first group contains three characteristic time parameters, namely: (1) te, which characterizes the Li-ion transport rate in the electrolyte phase, (2) ts, characterizing the lithium diffusion rate in the solid active materials, and (3) tc, describing the local Li-ion depletion rate in electrolyte phase at the electrolyte/electrode interface due to electrochemical reactions. The second group contains two electric resistance parameters: Re and Rs, which represent respectively, the equivalent ionic transport resistance and the effective electronic transport resistance in the electrode. Electrochemical modeling and simulations to the discharge process of LiCoO2 cells reveal that: (1) if te, ts and tc are on the same order of magnitude, the species transports may not cause any performance limitations to the battery; (2) the underlying mechanisms of performance limitations due to thick electrode, high-rate operation, and large-sized active material particles as well as effects of charge transports are revealed. The findings may be used as quantitative guidelines in the development and design of more advanced Li-ion batteries. PMID:27599870

  11. Elucidating the Performance Limitations of Lithium-ion Batteries due to Species and Charge Transport through Five Characteristic Parameters.

    PubMed

    Jiang, Fangming; Peng, Peng

    2016-01-01

    Underutilization due to performance limitations imposed by species and charge transports is one of the key issues that persist with various lithium-ion batteries. To elucidate the relevant mechanisms, two groups of characteristic parameters were proposed. The first group contains three characteristic time parameters, namely: (1) te, which characterizes the Li-ion transport rate in the electrolyte phase, (2) ts, characterizing the lithium diffusion rate in the solid active materials, and (3) tc, describing the local Li-ion depletion rate in electrolyte phase at the electrolyte/electrode interface due to electrochemical reactions. The second group contains two electric resistance parameters: Re and Rs, which represent respectively, the equivalent ionic transport resistance and the effective electronic transport resistance in the electrode. Electrochemical modeling and simulations to the discharge process of LiCoO2 cells reveal that: (1) if te, ts and tc are on the same order of magnitude, the species transports may not cause any performance limitations to the battery; (2) the underlying mechanisms of performance limitations due to thick electrode, high-rate operation, and large-sized active material particles as well as effects of charge transports are revealed. The findings may be used as quantitative guidelines in the development and design of more advanced Li-ion batteries. PMID:27599870

  12. Active limited-angle tomographic phase microscope.

    PubMed

    Kus, Arkadiusz; Krauze, Wojciech; Kujawinska, Malgorzata

    2015-01-01

    We demonstrate an active, holographic tomography system, working with limited angle of projections, realized by optical-only, diffraction-based beam steering. The system created for this purpose is a Mach–Zehnder interferometer modified to serve as a digital holographic microscope with a high numerical aperture illumination module and a spatial light modulator (SLM). Such a solution is fast and robust. Apart from providing an elegant solution to viewing angle shifting, it also adds new capabilities of the holographic microscope system. SLM, being an active optical element, allows wavefront correction in order to improve measurement accuracy. Integrated phase data captured with different illumination scenarios within a highly limited angular range are processed by a new tomographic reconstruction algorithm based on the compressed sensing technique: total variation minimization, which is applied here to reconstruct nonpiecewise constant samples. Finally, the accuracy of full measurement and the proposed processing path is tested for a calibrated three-dimensional micro-object as well as a biological object--C2C12 myoblast cell.

  13. Fundamental limitations on V/STOL terminal guidance due to aircraft characteristics

    NASA Technical Reports Server (NTRS)

    Wolkovitch, J.; Lamont, C. W.; Lochtie, D. W.

    1971-01-01

    A review is given of limitations on approach flight paths of V/STOL aircraft, including limits on descent angle due to maximum drag/lift ratio. A method of calculating maximum drag/lift ratio of tilt-wing and deflected slipstream aircraft is presented. Derivatives and transfer functions for the CL-84 tilt-wing and X-22A tilt-duct aircraft are presented. For the unaugmented CL-84 in steep descents the transfer function relating descent angle to thrust contains a right-half plane zero. Using optimal control theory, it is shown that this zero causes a serious degradation in the accuracy with which steep flight paths can be followed in the presence of gusts.

  14. Energy and power limits for microbial activity

    NASA Astrophysics Data System (ADS)

    LaRowe, D.; Amend, J.

    2014-12-01

    The goal of this presentation is to describe a quantitative framework for determining how energy limits microbial activity, biomass and, ultimately, biogeochemical processes. Although this model can be applied to any environment, its utility is demonstrated in marine sediments, which are an attractive test habitat because they encompass a broad spectrum of energy levels, varying amounts of biomass and are ubiquitous. The potential number of active microbial cells in Arkonas Basin (Baltic Sea) sediments are estimated as a function of depth by quantifying the amount of energy that is available to them and the rate at which it is supplied: power. The amount of power supplied per cubic centimeter of sediment is determined by calculating the Gibbs energy of fermentation and sulfate reduction in combination with the rate of particulate organic carbon, POC, degradation. The Reactive Continuum Model (Boudreau and Ruddick, 1991), RCM, is used to determine the rate at which POC is made available for microbial consumption. The RCM represents POC as containing a range of different types of organic compounds whose ability to be consumed by microorganisms varies as a function of the age of the sediment and on the distribution of compound types that were initially deposited. The sediment age model and RCM parameters determined by (Mogollon et al., 2012) are used. The power available for fermentation and sulfate reduction coupled to H2 and acetate oxidation varies from 10-8 W cm-3 at the sediment water interface to between 10-11 - 10-12 W cm-3 at 3.5 meters below the seafloor, mbsf. Using values of maintenance powers for each of these catabolic activities taken from the literature, the total number of active cells in these sediments similarly decreases from just less than 108 cell cm-3 at the SWI to 4.6 x 104 cells cm-3 at 3.5 mbsf. The number of moles of POC decreases from 2.6 x 10-5 to 9.5 x 10-6, also becoming more recalcitrant with depth. Boudreau, B. P. and Ruddick, B. R

  15. Limitations of signal averaging due to temporal correlation in laser remote-sensing measurements

    NASA Technical Reports Server (NTRS)

    Menyuk, N.; Killinger, D. K.; Menyuk, C. R.

    1982-01-01

    Laser remote sensing involves the measurement of laser-beam transmission through the atmosphere and is subject to uncertainties caused by strong fluctuations due primarily to speckle, glint, and atmospheric-turbulence effects. These uncertainties are generally reduced by taking average values of increasing numbers of measurements. An experiment was carried out to directly measure the effect of signal averaging on back-scattered laser return signals from a diffusely reflecting target using a direct-detection differential-absorption lidar (DIAL) system. The improvement in accuracy obtained by averaging over increasing numbers of data points was found to be smaller than that predicted for independent measurements. The experimental results are shown to be in excellent agreement with a theoretical analysis which considers the effect of temporal correlation. The analysis indicates that small but long-term temporal correlation severely limits the improvement available through signal averaging.

  16. Fundamental Limit of 1/f Frequency Noise in Semiconductor Lasers Due to Mechanical Thermal Noise

    NASA Technical Reports Server (NTRS)

    Numata, K.; Camp, J.

    2011-01-01

    So-called 1/f noise has power spectral density inversely proportional to frequency, and is observed in many physical processes. Single longitudinal-mode semiconductor lasers, used in variety of interferometric sensing applications, as well as coherent communications, exhibit 1/f frequency noise at low frequency (typically below 100kHz). Here we evaluate mechanical thermal noise due to mechanical dissipation in semiconductor laser components and give a plausible explanation for the widely-observed 1/f frequency noise, applying a methodology developed for fixed-spacer cavities for laser frequency stabilization. Semiconductor-laser's short cavity, small beam radius, and lossy components are expected to emphasize thermal-noise-limited frequency noise. Our simple model largely explains the different 1/f noise levels observed in various semiconductor lasers, and provides a framework where the noise may be reduced with proper design.

  17. Major geomagnetic storm due to solar activity (2006-2013).

    NASA Astrophysics Data System (ADS)

    Tiwari, Bhupendra Kumar

    Major geomagnetic storm due to solar activity (2006-2013). Bhupendra Kumar Tiwari Department of Physics, A.P.S.University, Rewa(M.P.) Email: - btiwtari70@yahoo.com mobile 09424981974 Abstract- The geospace environment is dominated by disturbances created by the sun, it is observed that coronal mass ejection (CME) and solar flare events are the causal link to solar activity that produces geomagnetic storm (GMS).CMEs are large scale magneto-plasma structures that erupt from the sun and propagate through the interplanetary medium with speeds ranging from only a few km/s to as large as 4000 km/s. When the interplanetary magnetic field associated with CMEs impinges upon the earth’s magnetosphere and reconnect occur geomagnetic storm. Based on the observation from SOHO/LASCO spacecraft for solar activity and WDC for geomagnetism Kyoto for geomagnetic storm events are characterized by the disturbance storm time (Dst) index during the period 2006-2013. We consider here only intense geomagnetic storm Dst <-100nT, are 12 during 2006-2013.Geomagnetic storm with maximum Dst< -155nT occurred on Dec15, 2006 associated with halo CME with Kp-index 8+ and also verify that halo CME is the main cause to produce large geomagnetic storms.

  18. Limits to Seeing High-Redshift Galaxies Due to Planck-Scale-Induced Blurring

    NASA Astrophysics Data System (ADS)

    Steinbring, Eric

    2015-08-01

    Carefully accounting for cosmological surface-brightness dimming and K-corrections are two important steps in teasing out the underlying properties of evolving high-z galaxy populations. Another potential effect is worthy of scrutiny simply because of its profound physical implications, if seen. In the last decade or so there has been debate over the possibility that the fuzzy quantum nature of spacetime might decohere wavefronts emanating from very distant sources. Consequences of that could be "blurred" or "faded" images of compact structures in galaxies, primarily at z>1 for their emitted X-rays and gamma-rays, but perhaps even in UV through optical light at higher redshift. So far there are only inconclusive hints of this from z~4 active-galactic nucleii and gamma-ray bursts viewed with Fermi and Hubble Space Telescope. If correct though, that would impose a significant, fundamental resolution limit for galaxies out to z~8 in the era of the James Webb Space Telescope and the next generation of ground-based telescopes using adaptive optics. I consider what to look for (and maybe not see).

  19. Energy deposition in the earth's atmosphere due to impact of solar activity-generated disturbances

    NASA Technical Reports Server (NTRS)

    Wu, S. T.; Kan, L. C.; Tandberg-Hanssen, E.; Dryer, M.

    1979-01-01

    Energy deposition in and dynamic responses of the terrestrial atmosphere to solar flare-generated shocks and other physical processes - such as particle precipitation and local heating - are investigated self-consistently in the context of hydrodynamics, the problem being treated as an initial boundary-value problem. It is extremely difficult to construct a general model for the line solar activity-magnetosphere-atmosphere; however, a limited model for this link is possible. The paper describes such a model, and presents some results on energy deposition into the earth's atmosphere due to solar activity-generated disturbances. Results from the present calculations are presented and discussed.

  20. The Limit of Free Magnetic Energy in Active Regions

    NASA Technical Reports Server (NTRS)

    Moore, Ron; Falconer, David; Sterling, Alphonse

    2012-01-01

    By measuring from active-region magnetograms a proxy of the free energy in the active region fs magnetic field, it has been found previously that (1) there is an abrupt upper limit to the free energy the field can hold that increases with the amount of magnetic field in the active region, the active region fs magnetic flux content, and (2) the free energy is usually near its limit when the field explodes in a CME/flare eruption. That is, explosive active regions are concentrated in a main-sequence path bordering the free-energy ]limit line in (flux content, free-energy proxy) phase space. Here, from measurement of Marshall Space Flight Center vector magnetograms, we find the magnetic condition that underlies the free ]energy limit and the accompanying main sequence of explosive active regions. Using a suitable free ]energy proxy measured from vector magnetograms of 44 active regions, we find that (1) in active regions at and near their free ]energy limit, the ratio of magnetic-shear free energy to the non ]free magnetic energy the potential field would have is approximately 1 in the core field, the field rooted along the neutral line, and (2) this ratio is progressively less in active regions progressively farther below their free ]energy limit. This shows that most active regions in which this core-field energy ratio is much less than 1 cannot be triggered to explode; as this ratio approaches 1, most active regions become capable of exploding; and when this ratio is 1 or greater, most active regions are compelled to explode. From these results we surmise the magnetic condition that determines the free ]energy limit is the ratio of the free magnetic energy to the non-free energy the active region fs field would have were it completely relaxed to its potential ]field configuration, and that this ratio is approximately 1 at the free-energy limit and in the main sequence of explosive active regions.

  1. Extraterrestrial solar flux measurement limitations due to a Beer's law assumption and uncertainty in local time.

    PubMed

    Thomason, L W; Herman, B M; Schotland, R M; Reagan, J A

    1982-04-01

    The dependence on bandwidth of the error in estimating both optical depth and extraterrestrial solar flux due to an assumption of Beer's law applicability across finite bandwidths is determined by a numerical integration of Beer's law across the bandwidth. It was found that for 0.1% accuracy, 100-A bandwidths suffice for central wavelengths of 0.45 microm or greater; the maximum width yielding 0.1% accuracy decreases rapidly for shorter wavelengths. The accuracy to which solar elevation angle must be known to yield 0.1% accuracy is also examined and found to be a noteworthy though noncritical effect.

  2. Changes in osteoblastic activity due to simulated weightless conditions

    NASA Technical Reports Server (NTRS)

    Doty, S. B.; Morey-Holton, E. R.

    1982-01-01

    Using histochemistry and electron microscopy, the reduced bone formation which occurs in the hypokinetic, orthostatically treated adult rat has been studied. The two major changes noted occurred in the osteoblast population, indicated by a reduced alkaline phosphatase activity and reduced numbers of gap junctions between cells. These results were most noticeable in the periosteum and endosteum of the long bones. Changes in osteoblasts lining the surface of trabecular bone were not as evident. These results indicate that the cells lining the surfaces of weight bearing bones are most affected by hypokinesia and this reduction in cellular activity may be a mechanically induced effect.

  3. Analysis of exposure due to work on activated components

    SciTech Connect

    Cossairt, J.D.

    1987-09-01

    In this brief note the author summarized analysis of the exposure incurred in various maintenance jobs involving activated accelerator and beam line components at Fermilab. A tabulation was made of parameters associated with each job. Included are rather terse descriptions of the various tasks. The author presented various plots of the quantities in the table. All exposure rates are mR/hr while all exposures accumulated are mR. The exposure rates were generally measured at the Fermilab standard one foot distance from the activated component. Accumulated exposures are taken from the self-reading pocket dosimeter records maintained by the radiation control technicians.

  4. Recent decline in the global land evapotranspiration trend due to limited moisture supply.

    PubMed

    Jung, Martin; Reichstein, Markus; Ciais, Philippe; Seneviratne, Sonia I; Sheffield, Justin; Goulden, Michael L; Bonan, Gordon; Cescatti, Alessandro; Chen, Jiquan; de Jeu, Richard; Dolman, A Johannes; Eugster, Werner; Gerten, Dieter; Gianelle, Damiano; Gobron, Nadine; Heinke, Jens; Kimball, John; Law, Beverly E; Montagnani, Leonardo; Mu, Qiaozhen; Mueller, Brigitte; Oleson, Keith; Papale, Dario; Richardson, Andrew D; Roupsard, Olivier; Running, Steve; Tomelleri, Enrico; Viovy, Nicolas; Weber, Ulrich; Williams, Christopher; Wood, Eric; Zaehle, Sönke; Zhang, Ke

    2010-10-21

    More than half of the solar energy absorbed by land surfaces is currently used to evaporate water. Climate change is expected to intensify the hydrological cycle and to alter evapotranspiration, with implications for ecosystem services and feedback to regional and global climate. Evapotranspiration changes may already be under way, but direct observational constraints are lacking at the global scale. Until such evidence is available, changes in the water cycle on land−a key diagnostic criterion of the effects of climate change and variability−remain uncertain. Here we provide a data-driven estimate of global land evapotranspiration from 1982 to 2008, compiled using a global monitoring network, meteorological and remote-sensing observations, and a machine-learning algorithm. In addition, we have assessed evapotranspiration variations over the same time period using an ensemble of process-based land-surface models. Our results suggest that global annual evapotranspiration increased on average by 7.1 ± 1.0 millimetres per year per decade from 1982 to 1997. After that, coincident with the last major El Niño event in 1998, the global evapotranspiration increase seems to have ceased until 2008. This change was driven primarily by moisture limitation in the Southern Hemisphere, particularly Africa and Australia. In these regions, microwave satellite observations indicate that soil moisture decreased from 1998 to 2008. Hence, increasing soil-moisture limitations on evapotranspiration largely explain the recent decline of the global land-evapotranspiration trend. Whether the changing behaviour of evapotranspiration is representative of natural climate variability or reflects a more permanent reorganization of the land water cycle is a key question for earth system science.

  5. Effects of activity interference on annoyance due to aircraft noise

    NASA Technical Reports Server (NTRS)

    Willshire, K. F.; Powell, C. A.

    1981-01-01

    The effects of aircraft flyover noise on annoyance were compared for face to face conversation, reverie, and television viewing. Eighteen 5 minute sessions, each composed of three flyovers, were presented on each of 2 days to subjects in a simulated living room. Twelve pairs of females and 12 pairs of males were tested, once before and once after work. Flyovers varied in peak noise level from 53 to 83 dB, A weighted. On each day, subjects engaged in 18 sessions, six of conversation, six of television viewing, and six of reverie. The subjects completed subjective ratings of annoyance and acceptability following every session. Annoyance and unacceptability rating scores were significantly higher for the activity of television viewing compared to conversation or reverie. There was no difference between judgments during the latter two activities. No differences were found in the judgments when compared on the basis of "fatigue" (before/after work) or sex of the subject.

  6. Stored energy in metallic glasses due to strains within the elastic limit

    NASA Astrophysics Data System (ADS)

    Greer, A. L.; Sun, Y. H.

    2016-06-01

    Room temperature loading of metallic glasses, at stresses below the macroscopic yield stress, raises their enthalpy and causes creep. Thermal cycling of metallic glasses between room temperature and 77 K also raises their enthalpy. In both cases, the enthalpy increases are comparable to those induced by heavy plastic deformation, but, as we show, the origins must be quite different. For plastic deformation, the enthalpy increase is a fraction (<10%) of the work done (WD) (and, in this sense, the behaviour is similar to that of conventional polycrystalline metals and alloys). In contrast, the room temperature creep and the thermal cycling involve small strains well within the elastic limit; in these cases, the enthalpy increase in the glass exceeds the WD, by as much as three orders of magnitude. We argue that the increased enthalpy can arise only from an endothermic disordering process drawing heat from the surroundings. We examine the mechanisms of this process. The increased enthalpy ('stored energy') is a measure of rejuvenation and appears as an exothermic heat of relaxation on heating the glass. The profile of this heat release (the 'relaxation spectrum') is analysed for several metallic glasses subjected to various treatments. Thus, the effects of the small-strain processing (creep and thermal cycling) can be better understood, and we can explore the potential for improving properties, in particular the plasticity, of metallic glasses. Metallic glasses can exhibit a wide range of enthalpy at a given temperature, and small-strain processing may assist in accessing this for practical purposes.

  7. Continuum modeling and limit equilibrium analysis of slope movement due to rainfall infiltration

    NASA Astrophysics Data System (ADS)

    Borja, Ronaldo; White, Joshua; Wu, Wei

    2010-05-01

    Hydrologically-driven landslides and debris flows are highly destructive events that threaten lives and critical infrastructure worldwide. Despite decades of extensive slope stability model development, the fundamental controls connecting the hydrologic and geotechnical processes that trigger slope failure are not well quantified. We use a fully coupled, physics-based finite element model to address this shortcoming. We develop and test a 3D continuum slope-deformation model that couples solid-deformation with fluid-flow processes in variably saturated soils, and assess the capability of the coupled model to predict stresses and deformation necessary to trigger slope failure. We then compare the continuum model with traditional limit equilibrium solutions based on the modified Bishop method of slices to assess the stability of the slope as a function of rainfall infiltration using a scalar stability indicator called factor of safety. For this assessment, we use extensive measurements from a densely instrumented mountain slope (The Coos Bay Experimental Catchment) where a large, rainfall-triggered slope failure occurred. The use of sophisticated, fully coupled numerical simulations combined with comprehensive field-measurements provides an unprecedented opportunity to advance the state of understanding of landslide failure processes and effective mitigation measures.

  8. Flame acceleration due to wall friction: Accuracy and intrinsic limitations of the formulations

    NASA Astrophysics Data System (ADS)

    Demirgok, Berk; Sezer, Hayri; Akkerman, V.'Yacheslav

    2015-11-01

    The analytical formulations on the premixed flame acceleration induced by wall friction in two-dimensional (2D) channels [Bychkov et al., Phys. Rev. E 72 (2005) 046307] and cylindrical tubes [Akkerman et al., Combust. Flame 145 (2006) 206] are revisited. Specifically, pipes with one end closed are considered, with a flame front propagating from the closed pipe end to the open one. The original studies provide the analytical formulas for the basic flame and fluid characteristics such as the flame acceleration rate, the flame shape and its propagation speed, as well as the flame-generated flow velocity profile. In the present work, the accuracy of these approaches is verified, computationally, and the intrinsic limitations and validity domains of the formulations are identified. Specifically, the error diagrams are presented to demonstrate how the accuracy of the formulations depends on the thermal expansion in the combustion process and the Reynolds number associated with the flame propagation. It is shown that the 2D theory is accurate enough for a wide range of parameters. In contrast, the zeroth-order approximation for the cylindrical configuration appeared to be quite inaccurate and had to be revisited. It is subsequently demonstrated that the first-order approximation for the cylindrical geometry is very accurate for realistically large thermal expansions and Reynolds numbers. Consequently, unlike the zeroth-order approach, the first-order formulation can constitute a backbone for the comprehensive theory of the flame acceleration and detonation initiation in cylindrical tubes. Cumulatively, the accuracy of the formulations deteriorates with the reduction of the Reynolds number and thermal expansion.

  9. Density increase due to active feedback in mirror machine

    NASA Astrophysics Data System (ADS)

    Seemann, Omri; Be'Ery, Ilan

    2014-10-01

    Mirror machines are one of the schemes for future fusion systems. Its main drawbacks are the flute instability and being open ended which results in plasma losses. A feedback system is used to stabilize the flute instability in a table top mirror machine with a continuous plasma source and RF heating. Under certain source density and temperature conditions, although the plasma was stabilized, plasma density increase was not measured. After decreasing the source density and increasing the temperature, Plasma density increase was achieved. It is theorized that these results are due to transition of the plasma main loss mechanism from collision dominated to instability dominated. In the former, the main density loss is through diffusion and In the latter, it is through flute instability which drives the plasma to the edge of the vacuum chamber. Future research directions are discussed for a planned machine which should achieve higher temperatures and better diagnostic capabilities. The research will focus on magnetic actuators and passive RF stabilization.

  10. Water Activity Limits the Hygroscopic Growth Factor of Organic Aerosols

    NASA Astrophysics Data System (ADS)

    Rodriguez, L. I.; Cabrera, J. A.; Golden, D.; Tabazadeh, A.

    2007-12-01

    In this work we study the hygroscopic behavior of organic aerosols, which has important implications for Earth's climate. The hygroscopic growth factor (HGF) is defined as the ratio of the diameter of a spherical particle when it is exposed to dry conditions to that at humid conditions. We present a new formulation to express the HGF of an aerosol particle as a function of water activity (aw) in the aqueous phase. This new formulation matches reported HGFs for common inorganic salts and water-miscible organic particles that are known to deliquesce into aqueous drops at high relative humidities (RH). Many studies use tandem differential mobility analyzers (TDMA) to determine the HGF of organic aerosols. For example, Brooks et al. used a TDMA to measure a HGF of 1.2 for 2 μm phthalic acid (PA) particles at 90% RH (aw= 0.9). However, water activity limits the growth of a particle that can be attributed to water uptake. We have assembled a vapor pressure apparatus to measure aw of aqueous solutions at room temperature. Measured water activities for PA, used in our growth formulation, yield a HGF of ~ 1.0005 for 2 μm PA particles at 90% RH. Comparing our results against Brooks et al. suggests that TDMA experiments may grossly overestimate the HGF of PA particles since water activity limits this growth to below 1.0005. Alternatively, we suggest that the adsorption of a negligible mass of water by a highly porous PA particle can lead to an apparent growth in particle size by changing its morphology. Other studies also use TDMAs to measure HGFs of secondary organic aerosols (SOAs). HGFs reported for SOAs are very similar to PA, suggesting that the observed growth may be due to morphological changes in particle size rather than water uptake as commonly assumed. We built a smog chamber where an organic precursor, such as d-limonene, reacts with nitrogen oxides under UV radiation to produce SOAs. We compare the HGFs for SOAs obtained with our method to those obtained with

  11. Cell organization in soft media due to active mechanosensing.

    PubMed

    Bischofs, I B; Schwarz, U S

    2003-08-01

    Adhering cells actively probe the mechanical properties of their environment and use the resulting information to position and orient themselves. We show that a large body of experimental observations can be consistently explained from one unifying principle, namely that cells strengthen contacts and cytoskeleton in the direction of large effective stiffness. Using linear elasticity theory to model the extracellular environment, we calculate optimal cell organization for several situations of interest and find excellent agreement with experiments for fibroblasts, both on elastic substrates and in collagen gels: cells orient in the direction of external tensile strain; they orient parallel and normal to free and clamped surfaces, respectively; and they interact elastically to form strings. Our method can be applied for rational design of tissue equivalents. Moreover, our results indicate that the concept of contact guidance has to be reevaluated. We also suggest that cell-matrix contacts are up-regulated by large effective stiffness in the environment because, in this way, build-up of force is more efficient.

  12. Reducing Conservatism in Aircraft Engine Response Using Conditionally Active Min-Max Limit Regulators

    NASA Technical Reports Server (NTRS)

    May, Ryan D.; Garg, Sanjay

    2012-01-01

    Current aircraft engine control logic uses a Min-Max control selection structure to prevent the engine from exceeding any safety or operational limits during transients due to throttle commands. This structure is inherently conservative and produces transient responses that are slower than necessary. In order to utilize the existing safety margins more effectively, a modification to this architecture is proposed, referred to as a Conditionally Active (CA) limit regulator. This concept uses the existing Min-Max architecture with the modification that limit regulators are active only when the operating point is close to a particular limit. This paper explores the use of CA limit regulators using a publicly available commercial aircraft engine simulation. The improvement in thrust response while maintaining all necessary safety limits is demonstrated in a number of cases.

  13. Factors limiting microbial activity in volcanic tuff at Yucca Mountain

    SciTech Connect

    Kieft, T.L.; Kovacik, W.P.; Taylor, J.

    1996-09-01

    Samples of tuff aseptically collected from 10 locations in the Exploratory Shaft Facility at the site of the proposed high-level nuclear waste repository at Yucca Mountain, Nevada Test Site were analyzed for microbiological populations, activities, and factors limiting microbial activity. Radiotracer assays ({sup 14}C-labeled organic substrate mineralization), direct microscopic counts, and plate counts were used. Radiolabeled substrates were glucose, acetate, and glutamate. Radiotracer experiments were carried out with and without moisture and inorganic nutrient amendments to determine factors limiting to microbial activities. Nearly all samples showed the presence of microorganisms with the potential to mineralize organic substrates. Addition of inorganic nutrients stimulated activities in a small number of samples. The presence of viable microbial communities within the tuff has implications for transport of contaminants.

  14. RADIOLOGICAL RELEASES DUE TO AIR AND SILICA DUST ACTIVATION IN EMPLACEMENT DRIFTS

    SciTech Connect

    J.S. Tang

    2003-05-07

    The purpose of this calculation is to determine the quantity and significance of annual Monitored Geologic Repository (MGR) subsurface normal radiological releases due to neutron activation of air and silica dust in emplacement drifts. This calculation includes the following items: (1) Calculate activation of ventilation airflow through emplacement drifts to quantify radioactive gaseous releases; and (2) Calculate the bounding potential activated silica dust concentration and releases. The sources of silica dust may arise from air supply to emplacement drifts as well as host rock around emplacement drifts. For this calculation, the source of dust is conservatively assumed to be the host rock (Assumption 3.6), which is subject to long-term neutron exposure resulting in saturated radioactivity. The scope of this calculation is limited to releases from activated air and silica dust only, excluding natural radioactive releases such as radon or releases from defective waste packages (breached or contaminated). This work supports the repository ventilation system design and Preclosure Safety Analysis. This includes MGR items classified as Quality Level 1, for example, the Uncanistered Spent Nuclear Fuel Waste Package (CRWMS M&O [Civilian Radioactive Waste Management and Operation Contractor] 1999a, page 7). Therefore, this calculation is subject to the requirements of the ''Quality Assurance Requirements and Description'' (DOE [U.S. Department of Energy] 2003). The performance of the calculation and development of this document are carried out in accordance with AP-3.12Q, ''Design Calculation and Analyses'' and LP-3.30Q-BSC, ''Hazards Analysis System''.

  15. Central Limit Theorem: New SOCR Applet and Demonstration Activity.

    PubMed

    Dinov, Ivo D; Christou, Nicolas; Sanchez, Juana

    2008-07-01

    Modern approaches for information technology based blended education utilize a variety of novel instructional, computational and network resources. Such attempts employ technology to deliver integrated, dynamically linked, interactive content and multifaceted learning environments, which may facilitate student comprehension and information retention. In this manuscript, we describe one such innovative effort of using technological tools for improving student motivation and learning of the theory, practice and usability of the Central Limit Theorem (CLT) in probability and statistics courses. Our approach is based on harnessing the computational libraries developed by the Statistics Online Computational Resource (SOCR) to design a new interactive Java applet and a corresponding demonstration activity that illustrate the meaning and the power of the CLT. The CLT applet and activity have clear common goals; to provide graphical representation of the CLT, to improve student intuition, and to empirically validate and establish the limits of the CLT. The SOCR CLT activity consists of four experiments that demonstrate the assumptions, meaning and implications of the CLT and ties these to specific hands-on simulations. We include a number of examples illustrating the theory and applications of the CLT. Both the SOCR CLT applet and activity are freely available online to the community to test, validate and extend (Applet: http://www.socr.ucla.edu/htmls/SOCR_Experiments.html and Activity: http://wiki.stat.ucla.edu/socr/index.php/SOCR_EduMaterials_Activities_GeneralCentralLimitTheorem). PMID:21833159

  16. Central Limit Theorem: New SOCR Applet and Demonstration Activity

    PubMed Central

    Dinov, Ivo D.; Christou, Nicolas; Sanchez, Juana

    2011-01-01

    Modern approaches for information technology based blended education utilize a variety of novel instructional, computational and network resources. Such attempts employ technology to deliver integrated, dynamically linked, interactive content and multifaceted learning environments, which may facilitate student comprehension and information retention. In this manuscript, we describe one such innovative effort of using technological tools for improving student motivation and learning of the theory, practice and usability of the Central Limit Theorem (CLT) in probability and statistics courses. Our approach is based on harnessing the computational libraries developed by the Statistics Online Computational Resource (SOCR) to design a new interactive Java applet and a corresponding demonstration activity that illustrate the meaning and the power of the CLT. The CLT applet and activity have clear common goals; to provide graphical representation of the CLT, to improve student intuition, and to empirically validate and establish the limits of the CLT. The SOCR CLT activity consists of four experiments that demonstrate the assumptions, meaning and implications of the CLT and ties these to specific hands-on simulations. We include a number of examples illustrating the theory and applications of the CLT. Both the SOCR CLT applet and activity are freely available online to the community to test, validate and extend (Applet: http://www.socr.ucla.edu/htmls/SOCR_Experiments.html and Activity: http://wiki.stat.ucla.edu/socr/index.php/SOCR_EduMaterials_Activities_GeneralCentralLimitTheorem). PMID:21833159

  17. Central Limit Theorem: New SOCR Applet and Demonstration Activity.

    PubMed

    Dinov, Ivo D; Christou, Nicolas; Sanchez, Juana

    2008-07-01

    Modern approaches for information technology based blended education utilize a variety of novel instructional, computational and network resources. Such attempts employ technology to deliver integrated, dynamically linked, interactive content and multifaceted learning environments, which may facilitate student comprehension and information retention. In this manuscript, we describe one such innovative effort of using technological tools for improving student motivation and learning of the theory, practice and usability of the Central Limit Theorem (CLT) in probability and statistics courses. Our approach is based on harnessing the computational libraries developed by the Statistics Online Computational Resource (SOCR) to design a new interactive Java applet and a corresponding demonstration activity that illustrate the meaning and the power of the CLT. The CLT applet and activity have clear common goals; to provide graphical representation of the CLT, to improve student intuition, and to empirically validate and establish the limits of the CLT. The SOCR CLT activity consists of four experiments that demonstrate the assumptions, meaning and implications of the CLT and ties these to specific hands-on simulations. We include a number of examples illustrating the theory and applications of the CLT. Both the SOCR CLT applet and activity are freely available online to the community to test, validate and extend (Applet: http://www.socr.ucla.edu/htmls/SOCR_Experiments.html and Activity: http://wiki.stat.ucla.edu/socr/index.php/SOCR_EduMaterials_Activities_GeneralCentralLimitTheorem).

  18. 77 FR 15003 - Passive Activity Losses and Credits Limited; Hearing

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-14

    ... Internal Revenue Service 26 CFR Part 1 RIN 1545-BJ33 Passive Activity Losses and Credits Limited; Hearing AGENCY: Internal Revenue Service (IRS), Treasury. ] ACTION: Notice of public hearing on proposed rulemaking. SUMMARY: This document provides notice of public hearing on proposed rulemaking regarding...

  19. 31 CFR 31.214 - Limitations on concurrent activities.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ASSET RELIEF PROGRAM Conflicts of Interest § 31.214 Limitations on concurrent activities. Treasury has... impermissible conflicts of interest. Accordingly, the following restrictions shall apply unless waived pursuant... entity assists Treasury in the acquisition, valuation, management, or disposition of specific...

  20. Absence of in vitro Procoagulant Activity in Immunoglobulin Preparations due to Activated Coagulation Factors

    PubMed Central

    Oviedo, Adriana E.; Bernardi, María E.; Guglielmone, Hugo A.; Vitali, María S.

    2015-01-01

    Summary Background Immunoglobulin (IG) products, including intravenous (IVIG) or subcutaneous (SCIG) immunoglobulins are considered safe and effective for medical therapy; however, a sudden and unexpected increase in thromboembolic events (TE) after administration of certain batches of IVIG products has been attributed to the presence of activated coagulation factors, mainly factor XIa. Our aims were to examine the presence of enduring procoagulant activity during the manufacturing process of IGs, with special focus on monitoring factor XIa, and to evaluate the presence of in vitro procoagulant activity attributed to coagulation factors in different lots of IVIG and SCIG. Methods Samples of different steps of IG purification, 19 lots of IVIG and 9 of SCIG were analyzed and compared with 1 commercial preparation of IVIG and 2 of SCIG, respectively. Factors II, VII, IX, XI and XIa and non-activated partial thromboplastin time (NAPTT) were assayed. Results The levels of factors II, VII, IX, X and XI were non-quantifiable once fraction II had been re-dissolved and in all analyzed lots of IVIG and SCIG. The level of factor XIa at that point was under the detection limits of the assay, and NAPTT yielded values greater than the control during the purification process. In SCIG, we detected higher concentrations of factor XIa in the commercial products, which reached values up to 5 times higher than the average amounts found in the 9 batches produced by UNC-Hemoderivados. Factor XIa in commercial IVIG reached levels slightly higher than those of the 19 batches produced by UNC-Hemoderivados. Conclusion IVIG and SCIG manufactured by UNC-Hemoderivados showed a lack of thrombogenic potential, as demonstrated not only by the laboratory data obtained in this study but also by the absence of any reports of TE registered by the post marketing pharmacovigilance department. PMID:26733772

  1. Familial adult onset hyperinsulinism due to an activating glucokinase mutation: Implications for pharmacological glucokinase activation

    PubMed Central

    Challis, Benjamin G.; Harris, Julie; Sleigh, Alison; Isaac, Iona; Orme, Steve M.; Seevaratnam, Nandini; Dhatariya, Ketan; Simpson, Helen L.; Semple, Robert K.

    2016-01-01

    Context Glucokinase (GCK) phosphorylates and thereby “traps” glucose in cells, thus serving as a gatekeeper for cellular glucose metabolism, particularly in hepatocytes and pancreatic beta cells. In humans, activating GCK mutations cause familial hyperinsulinaemic hypoglycaemia (GCK-HH), leading to keen interest in the potential of small molecule glucokinase activators (GKAs) as treatments for diabetes mellitus. Many such agents have been developed, however observation of side effects including hypertriglyceridaemia and hepatic steatosis have delayed their clinical development. Objective To describe the clinical presentation and metabolic profiles of affected family members in a kindred with familial hyperinsulinism of adult presentation due to a known activating mutation in GCK. Design Clinical, biochemical and metabolic assessment, and GCK sequencing in affected family members. Results In the 60 year-old female proband, hyperinsulinaemic hypoglycaemia (blood glucose 2.1mmol/mol, insulin 18pmol/l) was confirmed following 34 hours of fasting, however abdominal computed tomography (CT), pancreatic MRI, endoscopic ultrasound, octreotide scintigraphy and selective arterial calcium stimulation failed to localise an insulinoma. A prolonged OGTT revealed fasting hypoglycaemia that was exacerbated after glucose challenge, consistent with dysregulated glucose-stimulated insulin release. A heterozygous activating mutation, p.Val389Leu, in the glucokinase gene (GCK) was found in the proband and four other family members. Of these, two had been investigated elsewhere for recurrent hypoglycaemia in adulthood, while the other two adult relatives were asymptomatic despite profound hypoglycaemia. All three of the available family members with the p.Val389Leu mutation had normal serum lipid profiles, normal rates of fasting hepatic de novo lipogenesis and had hepatic triglyceride levels commensurate with their degree of adiposity. Conclusion Activating GCK mutations may

  2. Stochastic dynamics of coupled active particles in an overdamped limit

    NASA Astrophysics Data System (ADS)

    Ann, Minjung; Lee, Kong-Ju-Bock; Park, Pyeong Jun

    2015-10-01

    We introduce a model for Brownian dynamics of coupled active particles in an overdamped limit. Our system consists of several identical active particles and one passive particle. Each active particle is elastically coupled to the passive particle and there is no direct coupling among the active particles. We investigate the dynamics of the system with respect to the number of active particles, viscous friction, and coupling between the active and passive particles. For this purpose, we consider an intracellular transport process as an application of our model and perform a Brownian dynamics simulation using realistic parameters for processive molecular motors such as kinesin-1. We determine an adequate energy conversion function for molecular motors and study the dynamics of intracellular transport by multiple motors. The results show that the average velocity of the coupled system is not affected by the number of active motors and that the stall force increases linearly as the number of motors increases. Our results are consistent with well-known experimental observations. We also examine the effects of coupling between the motors and the cargo, as well as of the spatial distribution of the motors around the cargo. Our model might provide a physical explanation of the cooperation among active motors in the cellular transport processes.

  3. A Control Allocation System for Automatic Detection and Compensation of Phase Shift Due to Actuator Rate Limiting

    NASA Technical Reports Server (NTRS)

    Yildiz, Yidiray; Kolmanovsky, Ilya V.; Acosta, Diana

    2011-01-01

    This paper proposes a control allocation system that can detect and compensate the phase shift between the desired and the actual total control effort due to rate limiting of the actuators. Phase shifting is an important problem in control system applications since it effectively introduces a time delay which may destabilize the closed loop dynamics. A relevant example comes from flight control where aggressive pilot commands, high gain of the flight control system or some anomaly in the system may cause actuator rate limiting and effective time delay introduction. This time delay can instigate Pilot Induced Oscillations (PIO), which is an abnormal coupling between the pilot and the aircraft resulting in unintentional and undesired oscillations. The proposed control allocation system reduces the effective time delay by first detecting the phase shift and then minimizing it using constrained optimization techniques. Flight control simulation results for an unstable aircraft with inertial cross coupling are reported, which demonstrate phase shift minimization and recovery from a PIO event.

  4. Limiter

    DOEpatents

    Cohen, S.A.; Hosea, J.C.; Timberlake, J.R.

    1984-10-19

    A limiter with a specially contoured front face is provided. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution. This limiter shape accommodates the various power scrape-off distances lambda p, which depend on the parallel velocity, V/sub parallel/, of the impacting particles.

  5. Cloud condensation nuclei activation of limited solubility organic aerosol

    NASA Astrophysics Data System (ADS)

    Huff Hartz, Kara E.; Tischuk, Joshua E.; Chan, Man Nin; Chan, Chak K.; Donahue, Neil M.; Pandis, Spyros N.

    The cloud condensation nuclei (CCN) activation of 19 organic species with water solubilities ( Csat) ranging from 10 -4 to 10 2 g solute 100 g -1 H 2O was measured. The organic particles were generated by nebulization of an aqueous or an alcohol solution. Use of alcohols as solvents enables the measurement of low solubility, non-volatile organic CCN activity and reduces the likelihood of residual water in the aerosol. The activation diameter of organic species with very low solubility in water ( Csat<0.3 g 100 g -1 H 2O) is in agreement with Köhler theory using the bulk solubility (limited solubility case) of the organic in water. Many species, including 2-acetylbenzoic acid, aspartic acid, azelaic acid, glutamic acid, homophthalic acid, phthalic acid, cis-pinonic acid, and salicylic acid are highly CCN active in spite of their low solubility (0.3 g 100 g -1 H 2O< Csat<1 g 100 g -1 H 2O), and activate almost as if completely water soluble. The CCN activity of most species is reduced, if the particles are produced using non-aqueous solvents. The existence of the particles in a metastable state at low RH can explain the observed enhancement in CCN activity beyond the levels suggested by their solubility.

  6. Senescence of activated stellate cells limits liver fibrosis

    PubMed Central

    Krizhanovsky, Valery; Yon, Monica; Dickins, Ross A.; Hearn, Stephen; Simon, Janelle; Miething, Cornelius; Yee, Herman; Zender, Lars; Lowe, Scott W.

    2011-01-01

    Summary Cellular senescence acts as a potent mechanism of tumor suppression; however, its functional contribution to non-cancer pathologies has not been examined. Here we show that senescent cells accumulate in murine livers treated to produce fibrosis, a precursor pathology to cirrhosis. The senescent cells are derived primarily from activated hepatic stellate cells, which initially proliferate in response to liver damage and produce the extracellular matrix deposited in the fibrotic scar. In mice lacking key senescence regulators, stellate cells continue to proliferate, leading to excessive liver fibrosis. Furthermore, senescent activated stellate cells exhibit gene expression profile consistent with cell cycle exit, reduced secretion of extracellular matrix components, enhanced secretion of extracellular matrix degrading enzymes, and enhanced immune surveillance. Accordingly natural killer cells preferentially kill senescent activated stellate cells in vitro and in vivo, thereby facilitating the resolution of fibrosis. Therefore, the senescence program limits the fibrogenic response to acute tissue damage. PMID:18724938

  7. Mechanisms of physical activity limitation in chronic lung diseases.

    PubMed

    Vogiatzis, Ioannis; Zakynthinos, George; Andrianopoulos, Vasileios

    2012-01-01

    In chronic lung diseases physical activity limitation is multifactorial involving respiratory, hemodynamic, and peripheral muscle abnormalities. The mechanisms of limitation discussed in this paper relate to (i) the imbalance between ventilatory capacity and demand, (ii) the imbalance between energy demand and supply to working respiratory and peripheral muscles, and (iii) the factors that induce peripheral muscle dysfunction. In practice, intolerable exertional symptoms (i.e., dyspnea) and/or leg discomfort are the main symptoms that limit physical performance in patients with chronic lung diseases. Furthermore, the reduced capacity for physical work and the adoption of a sedentary lifestyle, in an attempt to avoid breathlessness upon physical exertion, cause profound muscle deconditioning which in turn leads to disability and loss of functional independence. Accordingly, physical inactivity is an important component of worsening the patients' quality of life and contributes importantly to poor prognosis. Identifying the factors which prevent a patient with lung disease to easily carry out activities of daily living provides a unique as well as important perspective for the choice of the appropriate therapeutic strategy.

  8. Sympathetic Activation is Associated with Exercise Limitation in COPD.

    PubMed

    Haarmann, Helge; Folle, Jan; Nguyen, Xuan Phuc; Herrmann, Peter; Heusser, Karsten; Hasenfuß, Gerd; Andreas, Stefan; Raupach, Tobias

    2016-10-01

    Exercise intolerance, skeletal muscle dysfunction, and reduced daily activity are central in COPD patients and closely related to quality of life and prognosis. Studies assessing muscle exercise have revealed an increase in sympathetic outflow as a link to muscle hypoperfusion and exercise limitation. Our primary hypothesis was that muscle sympathetic nerve activity (MSNA) correlates with exercise limitation in COPD. MSNA was evaluated at rest and during dynamic or static handgrip exercise. Additionally, we assessed heart rate, blood pressure, CO2 tension, oxygen saturation (SpO2), and breathing frequency. Ergospirometry was performed to evaluate exercise capacity. We assessed MSNA of 14 COPD patients and 8 controls. In patients, MSNA was negatively correlated with peak oxygen uptake (VO2% pred) (r = -0.597; p = 0.040). During dynamic or static handgrip exercise, patients exhibited a significant increase in MSNA, which was not observed in the control group. The increase in MSNA during dynamic handgrip was highly negatively correlated with peak exercise capacity in Watts (w) and peak oxygen uptake (VO2/kg) (r = -0.853; p = 0.002 and r = -0.881; p = 0.002, respectively). Our study reveals an association between increased MSNA and limited exercise capacity in patients with COPD. Furthermore, we found an increased sympathetic response to moderate physical exercise (handgrip), which may contribute to exercise intolerance in COPD. PMID:26829234

  9. Limiter

    DOEpatents

    Cohen, Samuel A.; Hosea, Joel C.; Timberlake, John R.

    1986-01-01

    A limiter with a specially contoured front face accommodates the various power scrape-off distances .lambda..sub.p, which depend on the parallel velocity, V.sub..parallel., of the impacting particles. The front face of the limiter (the plasma-side face) is flat with a central indentation. In addition, the limiter shape is cylindrically symmetric so that the limiter can be rotated for greater heat distribution.

  10. Laser-to-hot-electron conversion limitations in relativistic laser matter interactions due to multi-picosecond dynamics

    DOE PAGES

    Schollmeier, Marius; Sefkow, Adam B.; Geissel, Matthias; Arefiev, Alexey V.; Flippo, Kirk A.; Gaillard, Sandrine A.; Johnson, Randy P.; Kimmel, Mark W.; Offermann, Dustin T.; Rambo, Patrick K.; et al

    2015-04-20

    High-energy short-pulse lasers are pushing the limits of plasma-based particle acceleration, x-ray generation, and high-harmonic generation by creating strong electromagnetic fields at the laser focus where electrons are being accelerated to relativistic velocities. Understanding the relativistic electron dynamics is key for an accurate interpretation of measurements. We present a unified and self-consistent modeling approach in quantitative agreement with measurements and differing trends across multiple target types acquired from two separate laser systems, which differ only in their nanosecond to picosecond-scale rising edge. Insights from high-fidelity modeling of laser-plasma interaction demonstrate that the ps-scale, orders of magnitude weaker rising edge ofmore » the main pulse measurably alters target evolution and relativistic electron generation compared to idealized pulse shapes. This can lead for instance to the experimentally observed difference between 45 MeV and 75 MeV maximum energy protons for two nominally identical laser shots, due to ps-scale prepulse variations. Our results indicate that the realistic inclusion of temporal laser pulse profiles in modeling efforts is required if predictive capability and extrapolation are sought for future target and laser designs or for other relativistic laser ion acceleration schemes.« less

  11. Laser-to-hot-electron conversion limitations in relativistic laser matter interactions due to multi-picosecond dynamics

    SciTech Connect

    Schollmeier, Marius; Sefkow, Adam B.; Geissel, Matthias; Arefiev, Alexey V.; Flippo, Kirk A.; Gaillard, Sandrine A.; Johnson, Randy P.; Kimmel, Mark W.; Offermann, Dustin T.; Rambo, Patrick K.; Schwarz, Jens; Shimada, Tom

    2015-04-20

    High-energy short-pulse lasers are pushing the limits of plasma-based particle acceleration, x-ray generation, and high-harmonic generation by creating strong electromagnetic fields at the laser focus where electrons are being accelerated to relativistic velocities. Understanding the relativistic electron dynamics is key for an accurate interpretation of measurements. We present a unified and self-consistent modeling approach in quantitative agreement with measurements and differing trends across multiple target types acquired from two separate laser systems, which differ only in their nanosecond to picosecond-scale rising edge. Insights from high-fidelity modeling of laser-plasma interaction demonstrate that the ps-scale, orders of magnitude weaker rising edge of the main pulse measurably alters target evolution and relativistic electron generation compared to idealized pulse shapes. This can lead for instance to the experimentally observed difference between 45 MeV and 75 MeV maximum energy protons for two nominally identical laser shots, due to ps-scale prepulse variations. Our results indicate that the realistic inclusion of temporal laser pulse profiles in modeling efforts is required if predictive capability and extrapolation are sought for future target and laser designs or for other relativistic laser ion acceleration schemes.

  12. Ego depletion: is the active self a limited resource?

    PubMed

    Baumeister, R F; Bratslavsky, E; Muraven, M; Tice, D M

    1998-05-01

    Choice, active response, self-regulation, and other volition may all draw on a common inner resource. In Experiment 1, people who forced themselves to eat radishes instead of tempting chocolates subsequently quit faster on unsolvable puzzles than people who had not had to exert self-control over eating. In Experiment 2, making a meaningful personal choice to perform attitude-relevant behavior caused a similar decrement in persistence. In Experiment 3, suppressing emotion led to a subsequent drop in performance of solvable anagrams. In Experiment 4, an initial task requiring high self-regulation made people more passive (i.e., more prone to favor the passive-response option). These results suggest that the self's capacity for active volition is limited and that a range of seemingly different, unrelated acts share a common resource.

  13. Early life stress affects limited regional brain activity in depression.

    PubMed

    Du, Lian; Wang, Jingjie; Meng, Ben; Yong, Na; Yang, Xiangying; Huang, Qingling; Zhang, Yan; Yang, Lingling; Qu, Yuan; Chen, Zhu; Li, Yongmei; Lv, Fajin; Hu, Hua

    2016-05-03

    Early life stress (ELS) can alter brain function and increases the risk of major depressive disorder (MDD) in later life. This study investigated whether ELS contributes to differences in regional brain activity between MDD patients and healthy controls (HC), as measured by amplitude of low-frequency fluctuation (ALFF)/fractional (f)ALFF. Eighteen first-episode, treatment-naïve MDD patients and HC were assessed with the Childhood Trauma Questionnaire and resting-state functional magnetic resonance imaging. We compared ALFF/fALFF between MDD patients and HC, with or without controlling for ELS, and determined whether ELS level was correlated with regional brain activity in each group. After regressing out ELS, we found that ALFF increased in bilateral amygdala and left orbital/cerebellum, while fALFF decreased in left inferior temporal and right middle frontal gyri in MDD patients relative to controls. ELS positively correlated with regional activity in the left cerebellum in MDD and in the right post-central/inferior temporal/superior frontal cingulate, inferior frontal gyrus and bilateral cerebellum in HC. Our findings indicate that there is only very limited region showing correlation between ELS and brain activity in MDD, while diverse areas in HC, suggesting ELS has few impacts on MDD patients.

  14. Early life stress affects limited regional brain activity in depression

    PubMed Central

    Du, Lian; Wang, Jingjie; Meng, Ben; Yong, Na; Yang, Xiangying; Huang, Qingling; Zhang, Yan; Yang, Lingling; Qu, Yuan; Chen, Zhu; Li, Yongmei; Lv, Fajin; Hu, Hua

    2016-01-01

    Early life stress (ELS) can alter brain function and increases the risk of major depressive disorder (MDD) in later life. This study investigated whether ELS contributes to differences in regional brain activity between MDD patients and healthy controls (HC), as measured by amplitude of low-frequency fluctuation (ALFF)/fractional (f)ALFF. Eighteen first-episode, treatment-naïve MDD patients and HC were assessed with the Childhood Trauma Questionnaire and resting-state functional magnetic resonance imaging. We compared ALFF/fALFF between MDD patients and HC, with or without controlling for ELS, and determined whether ELS level was correlated with regional brain activity in each group. After regressing out ELS, we found that ALFF increased in bilateral amygdala and left orbital/cerebellum, while fALFF decreased in left inferior temporal and right middle frontal gyri in MDD patients relative to controls. ELS positively correlated with regional activity in the left cerebellum in MDD and in the right post-central/inferior temporal/superior frontal cingulate, inferior frontal gyrus and bilateral cerebellum in HC. Our findings indicate that there is only very limited region showing correlation between ELS and brain activity in MDD, while diverse areas in HC, suggesting ELS has few impacts on MDD patients. PMID:27138376

  15. Physical and chemical limitations to preparation of beta radioactive stents by direct neutron activation.

    PubMed

    Petelenz, Barbara; Rajchel, Bogusław; Bilski, Paweł; Misiak, Ryszard; Bartyzel, Mirosław; Wilczek, Krzysztof; Alber, Dorothea

    2003-02-01

    Pure beta emitters are the sources of choice for intracoronary irradiations in restenosis prevention. In this work we reconsidered preparation of low activity 32P sources by ion-implantation of stable 31P into highly biocompatible pure titanium stents, followed by neutron activation. Gamma-spectrometrical analysis has shown that during activations with high thermal neutrons flux production of gamma-active long-lived contaminants is much beyond the dosimetrically acceptable limit, mainly due to the competing (n,p) reactions induced by the fast neutrons on isotopes of the bulk stent material, and to a lesser extent due to (n,gamma) reactions on chemical impurities. A potential applicability of this method for obtaining alternative beta radioactive stents is discussed.

  16. MELANOPHORE BANDS AND AREAS DUE TO NERVE CUTTING, IN RELATION TO THE PROTRACTED ACTIVITY OF NERVES

    PubMed Central

    Parker, G. H.

    1941-01-01

    1. When appropriate chromatic nerves are cut caudal bands, cephalic areas, and the pelvic fins of the catfish Ameiurus darken. In pale fishes all these areas will sooner or later blanch. By recutting their nerves all such blanched areas will darken again. 2. These observations show that the darkening of caudal bands, areas, and fins on cutting their nerves is not due to paralysis (Brücke), to the obstruction of central influences such as inhibition (Zoond and Eyre), nor to vasomotor disturbances (Hogben), but to activities emanating from the cut itself. 3. The chief agents concerned with the color changes in Ameiurus are three: intermedin from the pituitary gland, acetylcholine from the dispersing nerves (cholinergic fibers), and adrenalin from the concentrating nerves (adrenergic fibers). The first two darken the fish; the third blanches it. In darkening the dispersing nerves appear to initiate the process and to be followed and substantially supplemented by intermedin. 4. Caudal bands blanch by lateral invasion, cephalic areas by lateral invasion and internal disintegration, and pelvic fins by a uniform process of general loss of tint equivalent to internal disintegration. 5. Adrenalin may be carried in such an oil as olive oil and may therefore act as a lipohumor; it is soluble in water and hence may act as a hydrohumor. In lateral invasion (caudal bands, cephalic areas) it probably acts as a lipohumor and in internal disintegration (cephalic areas, pelvic fins) it probably plays the part of a hydrohumor. 6. The duration of the activity of dispersing nerves after they had been cut was tested by means of the oscillograph, by anesthetizing blocks, and by cold-blocks. The nerves of Ameiurus proved to be unsatisfactory for oscillograph tests. An anesthetizing block, magnesium sulfate, is only partly satisfactory. A cold-block, 0°C., is successful to a limited degree. 7. By means of a cold-block it can be shown that dispersing autonomic nerve fibers in Ameiurus can

  17. Evaluation of Activity Concentration Values and Doses due to the Transport of Low Level Radioactive Material

    SciTech Connect

    Rawl, Richard R; Scofield, Patricia A; Leggett, Richard Wayne; Eckerman, Keith F

    2010-04-01

    The International Atomic Energy Agency (IAEA) initiated an international Coordinated Research Project (CRP) to evaluate the safety of transport of naturally occurring radioactive material (NORM). This report presents the United States contribution to that IAEA research program. The focus of this report is on the analysis of the potential doses resulting from the transport of low level radioactive material. Specific areas of research included: (1) an examination of the technical approach used in the derivation of exempt activity concentration values and a comparison of the doses associated with the transport of materials included or not included in the provisions of Paragraph 107(e) of the IAEA Safety Standards, Regulations for the Safe Transport of Radioactive Material, Safety Requirements No. TS-R-1; (2) determination of the doses resulting from different treatment of progeny for exempt values versus the A{sub 1}/A{sub 2} values; and (3) evaluation of the dose justifications for the provisions applicable to exempt materials and low specific activity materials (LSA-I). It was found that the 'previous or intended use' (PIU) provision in Paragraph 107(e) is not risk informed since doses to the most highly exposed persons (e.g., truck drivers) are comparable regardless of intended use of the transported material. The PIU clause can also have important economic implications for co-mined ores and products that are not intended for the fuel cycle but that have uranium extracted as part of their industrial processing. In examination of the footnotes in Table 2 of TS-R-1, which identifies the progeny included in the exempt or A1/A2 values, there is no explanation of how the progeny were selected. It is recommended that the progeny for both the exemption and A{sub 1}/A{sub 2} values should be similar regardless of application, and that the same physical information should be used in deriving the limits. Based on the evaluation of doses due to the transport of low-level NORM

  18. Limits of state activity in the interstate water market

    SciTech Connect

    Rodgers, A.B.

    1986-01-01

    In an effort to ensure future water supplies, many western states are becoming participants in the market for water. As market participants, states gain a proprietary interest in their water resources which more effectively secures their right to the water than mere regulation or claims of ownership under the public trust doctrine. As the author points out, however, the constitution imposes numerous limitations on state water market activity. The privileges and immunities clause, the commerce clause, the property clause, as well as the equal protection clause of the fourteenth amendment, all influence the manner in which states may behave. Most significantly, the author explains, these clauses prevent states from using their power as water market participants as a disguise for economic protectionism.

  19. Detection limit for activation measurements in ultralow background sites

    NASA Astrophysics Data System (ADS)

    Trache, Livius; Chesneanu, D.; Margineanu, R.; Pantelica, A.; Ghita, D. G.; Burducea, I.; Straticiuc, M.; Tang, X. D.

    2014-09-01

    We used 12C +13C fusion at the beam energies E = 6, 7 and 8 MeV to determine the sensitivity and the limits of activation method measurements in ultralow background sites. A 13C beam of 0.5 μA from the 3 MV Tandem accelerator of the Horia Hulubei National Institute of Physics and Nuclear Engineering - IFIN HH impinged on thick graphite targets. After about 24 hrs of irradiation targets were measured in two different laboratories: one with a heavy shielded Ge detector in the institute (at the surface) and one located underground in the microBequerel laboratory, in the salt mine of Slanic-Prahova, Romania. The 1369- and 2754 keV peaks from 24Na deactivation were clearly observed in the γ-ray spectra obtained for acquisitions lasting a few hours, or a few days. Determination of the detection limit in evaluating the cross sections for the target irradiated at Ec . m = 3 MeV indicates the fact that it is possible to measure gamma spectrum in underground laboratory down to Ec . m = 2 . 6 MeV. Cleaning the spectra with beta-gamma coincidences and increasing beam intensity 20 times will take as further down. The measurements are motivated by the study of the 12 C +12 C reaction at astrophysical energies.

  20. Carbon Limited Heterotrophic Activity in an Urban Stream

    NASA Astrophysics Data System (ADS)

    Hassett, B.; Bernhardt, E.; Palmer, M.

    2005-05-01

    Urban streams are characterized by flashy hydrographs, heavily incised channels, and scoured bed materials. Because of frequent scour, benthic organic matter in urban streams tends to be extremely low relative to nonurban streams. Recent research has related low organic matter availability to low rates of nitrogen uptake. We hypothesized that urban streams are carbon limited, and tested this hypothesis by adding a pulse of labile carbon (as potassium acetate) to the Stewart April tributary of Paint Branch, which drains a heavily urbanized watershed 73% impervious cover) in the suburbs of Washington, D.C. We predicted that the magnitude of the carbon effect on stream metabolism and N processing would be reduced as a result of litter inputs, and compared the stream response before and after peak litterfall. Adding labile dissolved organic carbon to the stream immediately increased metabolism in the stream channel during both additions, but this increase in heterotrophic activity did not lead to reductions in dissolved inorganic nitrogen concentrations. This indicates that while heterotrophs in this stream are carbon limited, the microbial community was not able to respond quickly enough to the pulse addition to appreciably reduce DIN concentrations in this eutrophic stream.

  1. Percentage of People with at Least One Activities of Daily Living (ADL) Limitation

    MedlinePlus

    ... ADL) Limitation Percentage of People with at Least One Activities of Daily Living (ADL) Limitation This measure ... Age Group Percentage of People with at Least One Activities of Daily Living Limitation by Age Group ...

  2. Limited contribution of common genetic variants to risk for liver injury due to a variety of drugs

    PubMed Central

    Urban, Thomas J.; Shen, Yufeng; Stolz, Andrew; Chalasani, Naga; Fontana, Robert J.; Rochon, James; Ge, Dongliang; Shianna, Kevin V.; Daly, Ann K.; Lucena, M. Isabel; Nelson, Matthew R.; Molokhia, Mariam; Aithal, Guruprasad P.; Floratos, Aris; Pe’er, Itsik; Serrano, Jose; Bonkovsky, Herbert; Davern, Timothy J.; Lee, William M.; Navarro, Victor J.; Talwalkar, Jayant A.; Goldstein, David B.; Watkins, Paul B.

    2013-01-01

    Background and aims Drug-induced liver injury (DILI) is a serious adverse drug event that is suspected to have a heritable component. We carried out a genome-wide association study of 783 individuals of European ancestry who experienced DILI due to more than 200 implicated drugs. Methods DILI patients from the US-based Drug-Induced Liver Injury Network (n = 401) and three international registries (n = 382) were genotyped with the Illumina 1Mduo BeadChip and compared with population controls (n = 3001). Potential associations were tested in 307 independent Drug-Induced Liver Injury Network cases. Results After accounting for known major histocompatibility complex risk alleles for flucloxacillin-DILI and amoxicillin/clavulanate-DILI, there were no genome-wide significant associations, including in the major histocompatibility complex region. Stratification of DILI cases according to clinical phenotypes (injury type, latency, age of onset) also did not show significant associations. An analysis of hepatocellular DILI (n = 285) restricted to 193 single-nucleotide polymorphisms previously associated with autoimmune disease showed a trend association for rs7574865, in the vicinity of signal transducer and activator of transcription 4 (STAT4) (P = 4.5 × 10−4). This association was replicated in an independent cohort of 168 hepatocellular DILI cases (P = 0.011 and 1.5 × 10−5 for combined cohorts). No significant associations were found with stratification by other clinical or demographic variables. Conclusion Although not significant at the genome-wide level, the association between hepatocellular DILI and STAT4 is consistent with the emerging role of the immune system in DILI. However, the lack of genome-wide association study findings supports the idea that strong genetic determinants of DILI may be largely drug-specific or may reflect rare genetic variations, which were not assessed in our study. PMID:22968431

  3. Temperature dependence of bromine activation due to reaction with ozone in a proxy for organic aerosols

    NASA Astrophysics Data System (ADS)

    Edebeli, Jacinta; Ammann, Markus; Gilgen, Anina; Eichler, Anja; Schneebeli, Martin; Bartels-Rausch, Thorsten

    2016-04-01

    The discovery of boundary layer ozone depletion events in the Polar Regions [1] and in the mid-latitudes [2], two areas of very different temperature regimes, begs the question of temperature dependence of reactions responsible for these observations [3]. These ODEs have been attributed to ozone reacting with halides leading to reactive halogens (halogen activation) of which bromide is extensively studied, R1 - R3 [4, 5] (R1 is a multiphase reaction). O3 + Br-→ O2 + OBr- (R1) OBr- + H+ ↔ HOBr (R2) HOBr + H+ + Br-→ Br2 + H2O (R3) Despite extensive studies of ozone-bromide interactions, the temperature dependence of bromine activation is not clear [3]. This limits parameterization of the involved reactions and factors in atmospheric models [3, 6]. Viscosity changes in the matrix (such as organic aerosols) due to temperature have been shown to influence heterogeneous reaction rates and products beyond pure temperature effect [7]. With the application of coated wall flow-tubes, the aim of this study is therefore to investigate the temperature dependence of bromine activation by ozone interaction while attempting to characterize the contributions of the bulk and surface reactions to observed ozone uptake. Citric acid is used in this study as a hygroscopically characterized matrix whose viscosity changes with temperature and humidity. Here, we present reactive ozone uptake measured between 258 and 289 K. The data show high reproducibility. Comparison of measured uptake with modelled bulk uptake at different matrix compositions (and viscosities) indicate that bulk reactive uptake dominates, but there are other factors which still need further consideration in the model. References 1. Barrie, L.A., et al., Nature, 1988. 334: p. 138 - 141. 2. Hebestreit, K., et al., Science, 1999. 283: p. 55-57. 3. Simpson, W.R., et al., Atmospheric Chemistry and Physics, 2007. 7: p. 4375 - 4418. 4. Haag, R.W. and J. Hoigné, Environ Sci Technol, 1983. 17: p. 261-267. 5. Oum, K.W., et

  4. Temperature dependence of bromine activation due to reaction with ozone in a proxy for organic aerosols

    NASA Astrophysics Data System (ADS)

    Edebeli, Jacinta; Ammann, Markus; Gilgen, Anina; Eichler, Anja; Schneebeli, Martin; Bartels-Rausch, Thorsten

    2016-04-01

    The discovery of boundary layer ozone depletion events in the Polar Regions [1] and in the mid-latitudes [2], two areas of very different temperature regimes, begs the question of temperature dependence of reactions responsible for these observations [3]. These ODEs have been attributed to ozone reacting with halides leading to reactive halogens (halogen activation) of which bromide is extensively studied, R1 - R3 [4, 5] (R1 is a multiphase reaction). O3 + Br‑→ O2 + OBr‑ (R1) OBr‑ + H+ ↔ HOBr (R2) HOBr + H+ + Br‑→ Br2 + H2O (R3) Despite extensive studies of ozone-bromide interactions, the temperature dependence of bromine activation is not clear [3]. This limits parameterization of the involved reactions and factors in atmospheric models [3, 6]. Viscosity changes in the matrix (such as organic aerosols) due to temperature have been shown to influence heterogeneous reaction rates and products beyond pure temperature effect [7]. With the application of coated wall flow-tubes, the aim of this study is therefore to investigate the temperature dependence of bromine activation by ozone interaction while attempting to characterize the contributions of the bulk and surface reactions to observed ozone uptake. Citric acid is used in this study as a hygroscopically characterized matrix whose viscosity changes with temperature and humidity. Here, we present reactive ozone uptake measured between 258 and 289 K. The data show high reproducibility. Comparison of measured uptake with modelled bulk uptake at different matrix compositions (and viscosities) indicate that bulk reactive uptake dominates, but there are other factors which still need further consideration in the model. References 1. Barrie, L.A., et al., Nature, 1988. 334: p. 138 - 141. 2. Hebestreit, K., et al., Science, 1999. 283: p. 55-57. 3. Simpson, W.R., et al., Atmospheric Chemistry and Physics, 2007. 7: p. 4375 - 4418. 4. Haag, R.W. and J. Hoigné, Environ Sci Technol, 1983. 17: p. 261-267. 5. Oum

  5. [Ergotism due to simultaneous use of ergot alkaloids and high activity antiretroviral therapy].

    PubMed

    Cifuentes M, Daniel; Blanco L, Sergio; Ramírez F, Camila

    2016-06-01

    High activity antiretroviral therapy may exacerbate the activity of ergot alkaloids due to an inhibition of cytochrome P450. We report a 57 years old female with AIDS treated with lamivudine, zidovudine, atazanavir, ritonavir and cotrimoxazole presenting with ischemic signs in the four limbs. There was acrocyanosis and weak radial and ulnar pulses. A family member referred that the patient used ergot alkaloids for headaches. An ergotism due to the simultaneous use of ergot alkaloids and antiretroviral therapy was suspected. The latter was discontinued and intravenous nitroglycerin, nifedipine and pentoxifyline were started with good results. PMID:27598502

  6. Years of Life Gained Due to Leisure-Time Physical Activity in the United States

    PubMed Central

    Janssen, Ian; Carson, Valerie; Lee, I-Min; Katzmarzyk, Peter T.; Blair, Steven N.

    2013-01-01

    Background Physical inactivity is an important modifiable risk factor for non-communicable disease. The degree to which physical activity affects the life expectancy of Americans is unknown. This study estimated the potential years of life gained due to leisure-time physical activity across the adult lifespan in the United States. Methods Data from the National Health and Nutrition Examination Survey (2007–2010), National Health Interview Study mortality linkage (1990–2006), and US Life Tables (2006) were used to estimate and compare life expectancy at each age of adult life for inactive (no moderate-to-vigorous physical activity), somewhat active (some moderate-to-vigorous activity but <500 metabolic equivalent min/week) and active (≥500 metabolic equivalent min/week of moderate-to-vigorous activity) adults. Analyses were conducted in 2012. Results Somewhat active and active non-Hispanic white men had a life expectancy at age 20 that was around 2.4 years longer than the inactive men; this life expectancy advantage was 1.2 years at age 80. Similar observations were made in non-Hispanic white women, with a higher life expectancy within the active category of 3.0 years at age 20 and 1.6 years at age 80. In non-Hispanic black women, as many as 5.5 potential years of life were gained due to physical activity. Significant increases in longevity were also observed within somewhat active and active non-Hispanic black men; however, among Hispanics the years of life gained estimates were more variable and not significantly different from 0 years gained. Conclusions Leisure-time physical activity is associated with increases in longevity in the United States. PMID:23253646

  7. 48 CFR 9903.201-8 - Compliant accounting changes due to external restructuring activities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Compliant accounting changes due to external restructuring activities. 9903.201-8 Section 9903.201-8 Federal Acquisition Regulations System COST ACCOUNTING STANDARDS BOARD, OFFICE OF FEDERAL PROCUREMENT POLICY, OFFICE OF MANAGEMENT AND BUDGET PROCUREMENT PRACTICES AND...

  8. Improved optical limiting performance of laser-ablation-generated metal nanoparticles due to silica-microsphere-induced local field enhancement.

    PubMed

    Du, Zheren; Chen, Lianwei; Kao, Tsung-Sheng; Wu, Mengxue; Hong, Minghui

    2015-01-01

    For practical application, optical limiting materials must exhibit a fast response and a low threshold in order to be used for the protection of the human eye and electro-optical sensors against intense light. Many nanomaterials have been found to exhibit optical limiting properties. Laser ablation offers the possibility of fabricating nanoparticles from a wide range of target materials. For practical use of these materials, their optical limiting performance, including optical limiting threshold and the ability to efficiently attenuate high intensity light, needs to be improved. In this paper, we fabricate nanoparticles of different metals by laser ablation in liquid. We study the optical nonlinear properties of the laser-generated nanoparticle dispersion. Silica microspheres are used to enhance the optical limiting performance of the nanoparticle dispersion. The change in the optical nonlinear properties of the laser-generated nanoparticle dispersion caused by silica microspheres is studied. It is found that the incident laser beam is locally focused by the microspheres, leading to an increased optical nonlinearity of the nanoparticle dispersion.

  9. Impaired voluntary neuromuscular activation limits muscle power in mobility-limited older adults

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Background. Age-related alterations of neuromuscular activation may contribute to deficits in muscle power and mobility function. This study assesses whether impaired activation of the agonist quadriceps and antagonist hamstrings, including amplitude- and velocity-dependent characteristics of activa...

  10. Approximation error method can reduce artifacts due to scalp blood flow in optical brain activation imaging

    NASA Astrophysics Data System (ADS)

    Heiskala, Juha; Kolehmainen, Ville; Tarvainen, Tanja; Kaipio, Jari. P.; Arridge, Simon R.

    2012-09-01

    Diffuse optical tomography can image the hemodynamic response to an activation in the human brain by measuring changes in optical absorption of near-infrared light. Since optodes placed on the scalp are used, the measurements are very sensitive to changes in optical attenuation in the scalp, making optical brain activation imaging susceptible to artifacts due to effects of systemic circulation and local circulation of the scalp. We propose to use the Bayesian approximation error approach to reduce these artifacts. The feasibility of the approach is evaluated using simulated brain activations. When a localized cortical activation occurs simultaneously with changes in the scalp blood flow, these changes can mask the cortical activity causing spurious artifacts. We show that the proposed approach is able to recover from these artifacts even when the nominal tissue properties are not well known.

  11. Allowable exposure limits for carbon dioxide during extravehicular activity

    NASA Technical Reports Server (NTRS)

    Seter, Andrew J.

    1993-01-01

    The intent was to review the research pertaining to human exposure to carbon dioxide (CO2) and to recommend allowable exposure limits for extravehicular activity (EVA). Respiratory, renal, and gastrointestinal systems may be adversely affected by chronic low dose CO2 exposure. Ventilation was increased 15 percent with 1 percent CO2 and 50 percent with 2 percent CO2. Chronic exposure to less than 2 percent CO2 led to 20 day cycles of uncompensated and compensated respiratory acidosis. Acid-base changes were small. Histopathologic changes in guinea pig lungs have been noted with long term exposure to 1 percent CO2. No changes were seen with exposure to 0.5 percent CO2. Cycling of bone calcium stores with associated changes in blood and urinary calcium levels occurs with long term CO2 exposure. Histologic changes in bone have been noted in guinea pigs exposed to 1 percent CO2. Renal calcification has been noted in guinea pigs with exposure to as low as 0.5 percent CO2. An increase in gastric acidity was noted in subjects with long term exposure to 1 percent CO2. Cardiovascular and neurologic function were largely unaffected. A decrease in the incidence of respiratory, renal, and gastrointestinal disease was noted in submariners coincident with a decrease in ambient CO2 from 1.2 percent to 0.8-0.9 percent. Oxygen (O2) and CO2 stimulate respiration independently and cumulatively. The addition of CO2 to high dose O2 led to the faster onset of seizure activity in mice. Experiments evaluating the physiologic responses to intermittent, repetitive exposures to low dose CO2 and 100 percent O2 mixtures should be performed. A reduction in the current NASA standard for CO2 exposure during EVA of 1 percent (7.6 mmHg) for nominal and 2 percent (15.2 mmHg) for heavy exertion to 0.5 percent (3.8 mmHg) for nominal and 1 percent (7.6 mmHg) for heavy exertion may be prudent. At a minimum, the current NASA standard should not be liberalized.

  12. Limitation of the achievable signal-to-noise ratio in optical coherence tomography due to mismatch of the balanced receiver.

    PubMed

    Rosa, Carla Carmelo; Podoleanu, Adrian Gh

    2004-09-01

    Owing to the limited spectral response of the fiber directional coupler used in a balanced optical coherence tomography configuration, the spectra are different in the two outputs. This affects unfavorably operation of the balanced photodetector unit. Excess photon noise makes a larger contribution than a directional coupler with a flat spectral response. A theoretical model is developed that shows that an optimum set of parameters may be defined to maximize the achievable signal-to-noise ratio. The model leads to a redefinition of the effective noise bandwidth, which takes into account the nonflat response of the directional coupler used. The model also predicts a limitation on the signal-to-noise ratio even when the stray reflectances in the interferometer are brought to zero. PMID:15449466

  13. Analytical Investigation of the Decrease in the Size of the Habitable Zone Due to a Limited CO2 Outgassing Rate

    NASA Astrophysics Data System (ADS)

    Abbot, Dorian S.

    2016-08-01

    The habitable zone concept is important because it focuses the scientific search for extraterrestrial life and aids the planning of future telescopes. Recent work has shown that planets near the outer edge of the habitable zone might not actually be able to stay warm and habitable if CO2 outgassing rates are not large enough to maintain high CO2 partial pressures against removal by silicate weathering. In this paper, I use simple equations for the climate and CO2 budget of a planet in the habitable zone that can capture the qualitative behavior of the system. With these equations I derive an analytical formula for an effective outer edge of the habitable zone, including limitations imposed by the CO2 outgassing rate. I then show that climate cycles between a snowball state and a warm climate are only possible beyond this limit if the weathering rate in the snowball climate is smaller than the CO2 outgassing rate (otherwise stable snowball states result). I derive an analytical solution for the climate cycles including a formula for their period in this limit. This work allows us to explore the qualitative effects of weathering processes on the effective outer edge of the habitable zone, which is important because weathering parameterizations are uncertain.

  14. [Severe disorders of mother-child interaction due to maternal depression--possibilities and limits of inpatient intervention].

    PubMed

    Verbeek, D; Schnitker, A; Schüren, A

    2004-02-01

    Described is the diagnostic, in-patient-treatment and evaluation of a mother-child-interaction disorder by a maternal depression. The therapy consisted of three elements: cognitive-behaviour therapy for the maternal depression, interaction training, socio-emotional development support. For therapy evaluation quantitative and qualitative data was collected at the beginning and the end of the treatment as well as after to half and one year. The results indicated positive effects on mother and child during the whole observation period. The chances and limits of this treatment are concludingly discussed. PMID:14992048

  15. Experimental evaluation of decrease in bacterial activity due to cell death and activity decay in activated sludge.

    PubMed

    Hao, Xiaodi; Wang, Qilin; Zhang, Xiangping; Cao, Yali; van Mark Loosdrecht, C M

    2009-08-01

    Decrease in bacterial activity (cell decay) in activated sludge can be attributed to cell death (reduction in the amount of active bacteria) and activity decay (reduction in the specific activity of active bacteria). The aim of this study was to experimentally differentiate between cell death and activity decay as a source of decrease in microbial activity. By means of measuring maximal oxygen uptake rates, verifying membrane integrity by live/dead staining and verifying presence of 16S rRNA with fluorescence in-situ hybridization, the decay rates and the death rates of ammonium oxidizing bacteria (AOB), nitrite oxidizing bacteria (NOB) and ordinary heterotrophic organisms (OHOs) were determined respectively in a nitrifying sequencing batch reactor (SBR) and a heterotrophic SBR. The experiments revealed that in the nitrifying system activity decay contributed 47% and 82% to the decreased activities of AOB and NOB and that cell death was responsible for 53% and 18% of decreases in their respective activities. In the heterotrophic system, activity decay took a share of 78% in the decreased activity of OHOs, and cell death was only responsible for 22% of decrease in their activity. The difference between the importance of cell death on the decreased activities of AOB and OHOs might be caused by the mechanisms of substrate storage and/or cryptic growth/death-regeneration of OHOs. The different nutrient sources for AOB and NOB might be the reason for a relatively smaller fraction of cell death in NOB.

  16. A proof of superlensing in the quasistatic regime, and limitations of superlenses in this regime due to anomalous localized resonance

    NASA Astrophysics Data System (ADS)

    Milton, Graeme W.; Nicorovici, Nicolae-Alexandru P.; McPhedran, Ross C.; Podolskiy, Viktor A.

    2005-12-01

    Enlarging upon work of Nicorovici, McPhedran & Milton (Nicorovici et al. 1994 Phys. Rev. B49(12), 8479-8482), a rigorous proof is given that in the quasistatic regime a cylindrical superlens can successfully image a dipole line source in the limit as the loss in the lens tends to zero. In this limit it is proved that the field magnitude diverges to infinity in two sometimes overlapping annular anomalously locally resonant regions, one of which extends inside the lens and the other of which extends outside the lens. The wavelength of the oscillations in the locally resonant regimes is set by the geometry and the loss, and goes to zero as the loss goes to zero. If the object or source being imaged responds to an applied field it is argued that it must lie outside the resonant regions to be successfully imaged. If the image is being probed it is argued that the resonant regions created by the probe should not surround the tip of the probe. These conditions taken together make it difficult to directly probe the potential in the near vicinity of the image of a source or object having small extent. The corresponding quasistatic results for the slab lens are also derived. If the source is too close to the slab lens, i.e. lying within the resonant region, then the power dissipation in the lens tends to infinity as the loss goes to zero, which makes the lens impractical for imaging such quasistatic sources. Perfect imaging in a cylindrical superlens is shown to extend to the static equations of magnetoelectricity or thermoelectricity, provided they have a special structure which makes these equations equivalent to the quasistatic equations.

  17. A Control Allocation Technique to Recover From Pilot-Induced Oscillations (CAPIO) Due to Actuator Rate Limiting

    NASA Technical Reports Server (NTRS)

    Yildiz, Yildiray; Kolmanovsky, Ilya V.

    2010-01-01

    This paper proposes a control allocation technique that can help pilots recover from pilot induced oscillations (PIO). When actuators are rate-saturated due to aggressive pilot commands, high gain flight control systems or some anomaly in the system, the effective delay in the control loop may increase depending on the nature of the cause. This effective delay increase manifests itself as a phase shift between the commanded and actual system signals and can instigate PIOs. The proposed control allocator reduces the effective time delay by minimizing the phase shift between the commanded and the actual attitude accelerations. Simulation results are reported, which demonstrate phase shift minimization and recovery from PIOs. Conversion of the objective function to be minimized and constraints to a form that is suitable for implementation is given.

  18. Limited impact of atmospheric nitrogen deposition on marine productivity due to biogeochemical feedbacks in a global ocean model

    NASA Astrophysics Data System (ADS)

    Somes, Christopher J.; Landolfi, Angela; Koeve, Wolfgang; Oschlies, Andreas

    2016-05-01

    The impact of increasing anthropogenic atmospheric nitrogen deposition on marine biogeochemistry is uncertain. We performed simulations to quantify its effect on nitrogen cycling and marine productivity in a global 3-D ocean biogeochemistry model. Nitrogen fixation provides an efficient feedback by decreasing immediately to deposition, whereas water column denitrification increases more gradually in the slowly expanding oxygen deficient zones. Counterintuitively, nitrogen deposition near oxygen deficient zones causes a net loss of marine nitrogen due to the stoichiometry of denitrification. In our idealized atmospheric deposition simulations that only account for nitrogen cycle perturbations, these combined stabilizing feedbacks largely compensate deposition and suppress the increase in global marine productivity to <2%, in contrast to a simulation that neglects nitrogen cycle feedbacks that predicts an increase of >15%. Our study emphasizes including the dynamic response of nitrogen fixation and denitrification to atmospheric nitrogen deposition to predict future changes of the marine nitrogen cycle and productivity.

  19. Out of control: Diminished prefrontal activity coincides with impaired motor performance due to choking under pressure

    PubMed Central

    Lee, Taraz G.; Grafton, Scott T.

    2014-01-01

    There are three non-exclusive theoretical explanations for the paradoxical collapse of performance due to large financial incentives. It has been proposed that “choking under pressure” is either due to distraction, interference via an increase in top-down control and performance monitoring, or excessive levels of arousal in the face of large losses. Given the known neural architecture involved in executive control and reward, we used fMRI of human participants during incentivized motor performance to provide evidence to support and/or reconcile these competing models in a visuomotor task. We show that the execution of a pre-trained motor task during neuroimaging is impaired by high rewards. BOLD activity occurring prior to movement onset is increased in dorsolateral prefrontal cortex and functional connectivity between this region and motor cortex is likewise increased just prior to choking. However, the extent of this increase in functional connectivity is inversely related to a participant's propensity to choke, suggesting that a failure in exerting top-down influence on motor control underlies choking under pressure due to large incentives. These results are consistent with a distraction account of choking and suggest that frontal influences on motor activity are necessary to protect performance from vulnerability under pressure. PMID:25449744

  20. LIMITED-USE CHEMICAL PROTECTIVE CLOTHING FOR EPA SUPERFUND ACTIVITIES

    EPA Science Inventory

    Because contractor field personnel complained about the poor durability and fit of limited-use chemical protective clothing (CPC) most commonly used at hazardous waste site operations, the U.S. Environmental Protection Agency (EPA) initiated a study to • characterize use of CPC...

  1. 76 FR 72875 - Passive Activity Losses and Credits Limited

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-28

    ... Department and the IRS promulgated temporary regulations under section 469 in 1988. See TD 8175, 53 FR 5686... limited partnership but constrains the individual taxpayer to only three of the seven regulatory tests in... individual taxpayer to demonstrate material participation through any of the seven regulatory tests in Sec....

  2. Biochemical changes in plant leaves as a biomarker of pollution due to anthropogenic activity.

    PubMed

    Thawale, P R; Satheesh Babu, S; Wakode, R R; Singh, Sanjeev Kumar; Kumar, Sunil; Juwarkar, A A

    2011-06-01

    The air pollution due to anthropogenic activities seriously affected human life, vegetation, and heritage as well. The vegetation cover in and around the city mitigates the air pollution by acting as a sink for pollution. An attempt was made to evaluate biochemical changes occurred in four selected plant species, namely Azadirachta indica, Mangifera indica, Delonix regia, and Cassia fistula of residential, commercial, and industrial areas of Nagpur city in India. It was observed that the correlated values of air pollutants and plant leaves characteristics alter foliar biochemical features (i.e., chlorophyll and ascorbic acid content, pH and relative water content) of plants due to air pollution. The changes in air pollution tolerance index of plants was also estimated which revealed that these plants can be used as a biomarker of air pollution.

  3. Influence of segmented vessel size due to limited imaging resolution on coronary hyperemic flow prediction from arterial crown volume.

    PubMed

    van Horssen, P; van Lier, M G J T B; van den Wijngaard, J P H M; VanBavel, E; Hoefer, I E; Spaan, J A E; Siebes, M

    2016-04-01

    Computational predictions of the functional stenosis severity from coronary imaging data use an allometric scaling law to derive hyperemic blood flow (Q) from coronary arterial volume (V), Q = αV(β) Reliable estimates of α and β are essential for meaningful flow estimations. We hypothesize that the relation between Q and V depends on imaging resolution. In five canine hearts, fluorescent microspheres were injected into the left anterior descending coronary artery during maximal hyperemia. The coronary arteries of the excised heart were filled with fluorescent cast material, frozen, and processed with an imaging cryomicrotome to yield a three-dimensional representation of the coronary arterial network. The effect of limited image resolution was simulated by assessing scaling law parameters from the virtual arterial network at 11 truncation levels ranging from 50 to 1,000 μm segment radius. Mapped microsphere locations were used to derive the corresponding relative Q using a reference truncation level of 200 μm. The scaling law factor α did not change with truncation level, despite considerable intersubject variability. In contrast, the scaling law exponent β decreased from 0.79 to 0.55 with increasing truncation radius and was significantly lower for truncation radii above 500 μm vs. 50 μm (P< 0.05). Hyperemic Q was underestimated for vessel truncation above the reference level. In conclusion, flow-crown volume relations confirmed overall power law behavior; however, this relation depends on the terminal vessel radius that can be visualized. The scaling law exponent β should therefore be adapted to the resolution of the imaging modality. PMID:26825519

  4. Influence of segmented vessel size due to limited imaging resolution on coronary hyperemic flow prediction from arterial crown volume.

    PubMed

    van Horssen, P; van Lier, M G J T B; van den Wijngaard, J P H M; VanBavel, E; Hoefer, I E; Spaan, J A E; Siebes, M

    2016-04-01

    Computational predictions of the functional stenosis severity from coronary imaging data use an allometric scaling law to derive hyperemic blood flow (Q) from coronary arterial volume (V), Q = αV(β) Reliable estimates of α and β are essential for meaningful flow estimations. We hypothesize that the relation between Q and V depends on imaging resolution. In five canine hearts, fluorescent microspheres were injected into the left anterior descending coronary artery during maximal hyperemia. The coronary arteries of the excised heart were filled with fluorescent cast material, frozen, and processed with an imaging cryomicrotome to yield a three-dimensional representation of the coronary arterial network. The effect of limited image resolution was simulated by assessing scaling law parameters from the virtual arterial network at 11 truncation levels ranging from 50 to 1,000 μm segment radius. Mapped microsphere locations were used to derive the corresponding relative Q using a reference truncation level of 200 μm. The scaling law factor α did not change with truncation level, despite considerable intersubject variability. In contrast, the scaling law exponent β decreased from 0.79 to 0.55 with increasing truncation radius and was significantly lower for truncation radii above 500 μm vs. 50 μm (P< 0.05). Hyperemic Q was underestimated for vessel truncation above the reference level. In conclusion, flow-crown volume relations confirmed overall power law behavior; however, this relation depends on the terminal vessel radius that can be visualized. The scaling law exponent β should therefore be adapted to the resolution of the imaging modality.

  5. An assessment of the resolution limitation due to radiation-damage in X-ray diffraction microscopy

    DOE PAGES

    Howells, M. R.; Beetz, T.; Chapman, H. N.; Cui, C.; Holton, J. M.; Jacobsen, C. J.; Kirz, J.; Lima, E.; Marchesini, S.; Miao, H.; et al

    2008-11-17

    X-ray diffraction microscopy (XDM) is a new form of x-ray imaging that is being practiced at several third-generation synchrotron-radiation x-ray facilities. Nine years have elapsed since the technique was first introduced and it has made rapid progress in demonstrating high-resolution three-dimensional imaging and promises few-nm resolution with much larger samples than can be imaged in the transmission electron microscope. Both life- and materials-science applications of XDM are intended, and it is expected that the principal limitation to resolution will be radiation damage for life science and the coherent power of available x-ray sources for material science. In this paper wemore » address the question of the role of radiation damage. We use a statistical analysis based on the so-called "dose fractionation theorem" of Hegerl and Hoppe to calculate the dose needed to make an image of a single life-science sample by XDM with a given resolution. We find that for simply-shaped objects the needed dose scales with the inverse fourth power of the resolution and present experimental evidence to support this finding. To determine the maximum tolerable dose we have assembled a number of data taken from the literature plus some measurements of our own which cover ranges of resolution that are not well covered otherwise. The conclusion of this study is that, based on the natural contrast between protein and water and "Rose-criterion" image quality, one should be able to image a frozen-hydrated biological sample using XDM at a resolution of about 10 nm.« less

  6. An assessment of the resolution limitation due to radiation-damage in X-ray diffraction microscopy

    SciTech Connect

    Howells, M. R.; Beetz, T.; Chapman, H. N.; Cui, C.; Holton, J. M.; Jacobsen, C. J.; Kirz, J.; Lima, E.; Marchesini, S.; Miao, H.; Sayre, D.; Shapiro, D. A.; Spence, J. C.H.; Starodub, D.

    2008-11-17

    X-ray diffraction microscopy (XDM) is a new form of x-ray imaging that is being practiced at several third-generation synchrotron-radiation x-ray facilities. Nine years have elapsed since the technique was first introduced and it has made rapid progress in demonstrating high-resolution three-dimensional imaging and promises few-nm resolution with much larger samples than can be imaged in the transmission electron microscope. Both life- and materials-science applications of XDM are intended, and it is expected that the principal limitation to resolution will be radiation damage for life science and the coherent power of available x-ray sources for material science. In this paper we address the question of the role of radiation damage. We use a statistical analysis based on the so-called "dose fractionation theorem" of Hegerl and Hoppe to calculate the dose needed to make an image of a single life-science sample by XDM with a given resolution. We find that for simply-shaped objects the needed dose scales with the inverse fourth power of the resolution and present experimental evidence to support this finding. To determine the maximum tolerable dose we have assembled a number of data taken from the literature plus some measurements of our own which cover ranges of resolution that are not well covered otherwise. The conclusion of this study is that, based on the natural contrast between protein and water and "Rose-criterion" image quality, one should be able to image a frozen-hydrated biological sample using XDM at a resolution of about 10 nm.

  7. Biodiversity loss in seagrass meadows due to local invertebrate fisheries and harbour activities

    NASA Astrophysics Data System (ADS)

    Nordlund, Lina Mtwana; Gullström, Martin

    2013-12-01

    Seagrass meadows provide a wide variety of ecosystem services, but their distribution and health are adversely affected by man. In the present study, we examined the influence of coastal exploitation in terms of invertebrate harvesting and harbour activity on invertebrate community composition in subtropical seagrass meadows at Inhaca Island, Mozambique, in the Western Indian Ocean. There was a fivefold higher invertebrate density and biomass, and clearly higher invertebrate species richness, in the protected (control) site compared to the two exploited sites. The causes for the clear differences between protected and exploited sites were probably a result of (1) the directional outtake of large edible or saleable invertebrates (mostly molluscs) and the absence of boat traffic in the harvested site, and (2) harbour activities. Invertebrate community composition in the two exploited sites also differed (although less clear), which was likely due to inherent distinction in type of disturbance. Our findings revealed that protection of seagrass habitat is necessary and that disturbances of different origin might require different forms of management and conservation. Designing protected areas is however a complex process due to competition for use and space with activities such as invertebrate harvesting and harbours.

  8. Subthreshold voltage noise due to channel fluctuations in active neuronal membranes.

    PubMed

    Steinmetz, P N; Manwani, A; Koch, C; London, M; Segev, I

    2000-01-01

    Voltage-gated ion channels in neuronal membranes fluctuate randomly between different conformational states due to thermal agitation. Fluctuations between conducting and nonconducting states give rise to noisy membrane currents and subthreshold voltage fluctuations and may contribute to variability in spike timing. Here we study subthreshold voltage fluctuations due to active voltage-gated Na+ and K+ channels as predicted by two commonly used kinetic schemes: the Mainen et al. (1995) (MJHS) kinetic scheme, which has been used to model dendritic channels in cortical neurons, and the classical Hodgkin-Huxley (1952) (HH) kinetic scheme for the squid giant axon. We compute the magnitudes, amplitude distributions, and power spectral densities of the voltage noise in isopotential membrane patches predicted by these kinetic schemes. For both schemes, noise magnitudes increase rapidly with depolarization from rest. Noise is larger for smaller patch areas but is smaller for increased model temperatures. We contrast the results from Monte Carlo simulations of the stochastic nonlinear kinetic schemes with analytical, closed-form expressions derived using passive and quasi-active linear approximations to the kinetic schemes. For all subthreshold voltage ranges, the quasi-active linearized approximation is accurate within 8% and may thus be used in large-scale simulations of realistic neuronal geometries.

  9. Limits to benthic feeding by eiders in a vital Arctic migration corridor due to localized prey and changing sea ice

    NASA Astrophysics Data System (ADS)

    Lovvorn, James R.; Rocha, Aariel R.; Jewett, Stephen C.; Dasher, Douglas; Oppel, Steffen; Powell, Abby N.

    2015-08-01

    Four species of threatened or declining eider ducks that nest in the Arctic migrate through the northeast Chukchi Sea, where anticipated industrial development may require prioritizing areas for conservation. In this nearshore corridor (10-40 m depth), the eiders' access to benthic prey during the spring is restricted to variable areas of open water within sea ice. For the most abundant species, the king eider (Somateria spectabilis), stable isotopes in blood cells, muscle, and potential prey indicate that these eiders ate mainly bivalves when traversing this corridor. Bivalves there were much smaller than the same taxa in deeper areas of the northern Bering Sea, possibly due to higher mortality rates caused by ice scour in shallow water; future decrease in seasonal duration of fast ice may increase this effect. Computer simulations suggested that if these eiders forage for >15 h/day, they can feed profitably at bivalve densities >200 m-2 regardless of water depth or availability of ice for resting. Sampling in 2010-2012 showed that large areas of profitable prey densities occurred only in certain locations throughout the migration corridor. Satellite data in April-May over 13 years (2001-2013) indicated that access to major feeding areas through sea ice in different segments of the corridor can vary from 0% to 100% between months and years. In a warming and increasingly variable climate, unpredictability of access may be enhanced by greater effects of shifting winds on unconsolidated ice. Our results indicate the importance of having a range of potential feeding areas throughout the migration corridor to ensure prey availability in all years. Spatial planning of nearshore industrial development in the Arctic, including commercial shipping, pipeline construction, and the risk of released oil, should consider these effects of high environmental variability on the adequacy of habitats targeted for conservation.

  10. Intrinsic rotation due to MHD activity in a tokamak with a resistive wall

    NASA Astrophysics Data System (ADS)

    Haines, M. G.; Gimblett, C. G.; Hastie, R. J.

    2013-05-01

    MHD activity in a tokamak, in the form of waves and instabilities, generally has a preferred direction for propagation in a two-fluid plasma. When the radial component of magnetic field associated with this activity interacts with a resistive wall, momentum or angular momentum will be given to the wall. The equal and opposite reaction will be on the plasma, in particular, for ideal and resistive modes, at the singular or resonant surfaces for the various modes. In this case the torque exerted is electromagnetic. This is in contrast to other mechanisms for intrinsic or spontaneous rotation which may arise at the plasma boundary. The resistive wall is considered generally, and the thin and thick wall limits found, the latter being relevant to ITER parameters. Remarkably small radial perturbing fields of order 0.1 G could produce a torque comparable in effect to the apparent anomalous toroidal viscosity.

  11. Active tissue factor and activated factor XI in circulating blood of patients with systolic heart failure due to ischemic cardiomyopathy

    PubMed Central

    Zabczyk, Michał; Butenas, Saulius; Palka, Ilona; Nessler, Jadwiga; Undas, Anetta

    2011-01-01

    INTRODUCTION Elevated clotting factors and thrombin generation have been reported to occur in patients with heart failure (HF). Circulating activated factor XI (FXIa) and active tissue factor (TF) can be detected in acute coronary syndromes and stable angina. OBJECTIVES We investigated circulating FXIa and active TF and their associations in patients with systolic HF due to ischemic cardiomyopathy. PATIENTS AND METHODS In an observational study, we assessed 53 consecutive patients, aged below 75 years, with stable HF associated with documented coronary artery disease (CAD). Atrial fibrillation (LA), recent thromboembolic events, and current anticoagulant therapy were the exclusion criteria. Plasma TF and FXIa activity was determined in clotting assays by measuring the response to inhibitory monoclonal antibodies. RESULTS Coagulant TF activity was detected in 20 patients (37.7%), and FXIa in 22 patients (41.5%). Patients with detectable TF activity and/or FXIa were younger, had a history of myocardial infarction more frequently, significantly higher F1+2 prothrombin fragments, larger LA and right ventricular diastolic diameter, and higher right ventricular systolic pressure than the remaining subjects (P ≤0.01 for all). Circulating FXIa was positively correlated with F1+2 levels (r = 0.69; P <0.001). CONCLUSIONS Circulating active TF and FXIa occurred in about 40% of patients with systolic HF due to ischemic cardiomyopathy. The presence of these factors was associated with enhanced thrombin formation. Associations between both factors and LA diameter and right ventricular parameters might suggest that TF and FXIa predispose to thromboembolic complications of HF. PMID:20864906

  12. Glycosphingolipid synthesis inhibition limits osteoclast activation and myeloma bone disease

    PubMed Central

    Ersek, Adel; Xu, Ke; Antonopoulos, Aristotelis; Butters, Terry D.; Santo, Ana Espirito; Vattakuzhi, Youridies; Williams, Lynn M.; Goudevenou, Katerina; Danks, Lynett; Freidin, Andrew; Spanoudakis, Emmanouil; Parry, Simon; Papaioannou, Maria; Hatjiharissi, Evdoxia; Chaidos, Aristeidis; Alonzi, Dominic S.; Twigg, Gabriele; Hu, Ming; Dwek, Raymond A.; Haslam, Stuart M.; Roberts, Irene; Dell, Anne; Rahemtulla, Amin; Horwood, Nicole J.; Karadimitris, Anastasios

    2015-01-01

    Glycosphingolipids (GSLs) are essential constituents of cell membranes and lipid rafts and can modulate signal transduction events. The contribution of GSLs in osteoclast (OC) activation and osteolytic bone diseases in malignancies such as the plasma cell dyscrasia multiple myeloma (MM) is not known. Here, we tested the hypothesis that pathological activation of OCs in MM requires de novo GSL synthesis and is further enhanced by myeloma cell–derived GSLs. Glucosylceramide synthase (GCS) inhibitors, including the clinically approved agent N-butyl-deoxynojirimycin (NB-DNJ), prevented OC development and activation by disrupting RANKL-induced localization of TRAF6 and c-SRC into lipid rafts and preventing nuclear accumulation of transcriptional activator NFATc1. GM3 was the prevailing GSL produced by patient-derived myeloma cells and MM cell lines, and exogenous addition of GM3 synergistically enhanced the ability of the pro-osteoclastogenic factors RANKL and insulin-like growth factor 1 (IGF-1) to induce osteoclastogenesis in precursors. In WT mice, administration of GM3 increased OC numbers and activity, an effect that was reversed by treatment with NB-DNJ. In a murine MM model, treatment with NB-DNJ markedly improved osteolytic bone disease symptoms. Together, these data demonstrate that both tumor-derived and de novo synthesized GSLs influence osteoclastogenesis and suggest that NB-DNJ may reduce pathological OC activation and bone destruction associated with MM. PMID:25915583

  13. CALCULATING ENERGY STORAGE DUE TO TOPOLOGICAL CHANGES IN EMERGING ACTIVE REGION NOAA AR 11112

    SciTech Connect

    Tarr, Lucas; Longcope, Dana

    2012-04-10

    The minimum current corona model provides a way to estimate stored coronal energy using the number of field lines connecting regions of positive and negative photospheric flux. This information is quantified by the net flux connecting pairs of opposing regions in a connectivity matrix. Changes in the coronal magnetic field, due to processes such as magnetic reconnection, manifest themselves as changes in the connectivity matrix. However, the connectivity matrix will also change when flux sources emerge or submerge through the photosphere, as often happens in active regions. We have developed an algorithm to estimate the changes in flux due to emergence and submergence of magnetic flux sources. These estimated changes must be accounted for in order to quantify storage and release of magnetic energy in the corona. To perform this calculation over extended periods of time, we must additionally have a consistently labeled connectivity matrix over the entire observational time span. We have therefore developed an automated tracking algorithm to generate a consistent connectivity matrix as the photospheric source regions evolve over time. We have applied this method to NOAA Active Region 11112, which underwent a GOES M2.9 class flare around 19:00 on 2010 October 16th, and calculated a lower bound on the free magnetic energy buildup of {approx}8.25 Multiplication-Sign 10{sup 30} erg over 3 days.

  14. A Krebs Cycle Component Limits Caspase Activation Rate through Mitochondrial Surface Restriction of CRL Activation.

    PubMed

    Aram, Lior; Braun, Tslil; Braverman, Carmel; Kaplan, Yosef; Ravid, Liat; Levin-Zaidman, Smadar; Arama, Eli

    2016-04-01

    How cells avoid excessive caspase activity and unwanted cell death during apoptotic caspase-mediated removal of large cellular structures is poorly understood. We investigate caspase-mediated extrusion of spermatid cytoplasmic contents in Drosophila during spermatid individualization. We show that a Krebs cycle component, the ATP-specific form of the succinyl-CoA synthetase β subunit (A-Sβ), binds to and activates the Cullin-3-based ubiquitin ligase (CRL3) complex required for caspase activation in spermatids. In vitro and in vivo evidence suggests that this interaction occurs on the mitochondrial surface, thereby limiting the source of CRL3 complex activation to the vicinity of this organelle and reducing the potential rate of caspase activation by at least 60%. Domain swapping between A-Sβ and the GTP-specific SCSβ (G-Sβ), which functions redundantly in the Krebs cycle, show that the metabolic and structural roles of A-Sβ in spermatids can be uncoupled, highlighting a moonlighting function of this Krebs cycle component in CRL activation.

  15. A Krebs Cycle Component Limits Caspase Activation Rate through Mitochondrial Surface Restriction of CRL Activation.

    PubMed

    Aram, Lior; Braun, Tslil; Braverman, Carmel; Kaplan, Yosef; Ravid, Liat; Levin-Zaidman, Smadar; Arama, Eli

    2016-04-01

    How cells avoid excessive caspase activity and unwanted cell death during apoptotic caspase-mediated removal of large cellular structures is poorly understood. We investigate caspase-mediated extrusion of spermatid cytoplasmic contents in Drosophila during spermatid individualization. We show that a Krebs cycle component, the ATP-specific form of the succinyl-CoA synthetase β subunit (A-Sβ), binds to and activates the Cullin-3-based ubiquitin ligase (CRL3) complex required for caspase activation in spermatids. In vitro and in vivo evidence suggests that this interaction occurs on the mitochondrial surface, thereby limiting the source of CRL3 complex activation to the vicinity of this organelle and reducing the potential rate of caspase activation by at least 60%. Domain swapping between A-Sβ and the GTP-specific SCSβ (G-Sβ), which functions redundantly in the Krebs cycle, show that the metabolic and structural roles of A-Sβ in spermatids can be uncoupled, highlighting a moonlighting function of this Krebs cycle component in CRL activation. PMID:27052834

  16. Activity Limitations among Young Adults with Developmental Disabilities: A Population-Based Follow-Up Study

    ERIC Educational Resources Information Center

    Braun, Kim Van Naarden; Yeargin-Allsopp, Marshalyn; Lollar, Donald

    2009-01-01

    Developmental disabilities are a heterogeneous group of chronic conditions that may result in substantial activity limitations. The type and number of limitations may vary by impairment characteristics. Economic and social constraints may impact activity limitations beyond those attributable to their impairment. Using the International…

  17. The Limits of Federal Activism in Education Policy

    ERIC Educational Resources Information Center

    Vergari, Sandra

    2012-01-01

    The evolution of the federal role in education policy has entailed increasing activism in matters traditionally controlled by states and school districts. However, the expanding federal role has not resulted in a zero sum game for states and localities. Focusing on the policy-implementation process, this article examines recent state and local…

  18. Brazing of the Tore Supra actively cooled Phase III Limiter

    SciTech Connect

    Nygren, R.E.; Walker, C.A.; Lutz, T.J.; Hosking, F.M.; McGrath, R.T.

    1993-12-31

    The head of the water-cooled Tore Supra Phase 3 Limiter is a bank of 14 round OFHC copper tubes, curved to fit the plasma radius, onto which several hundred pyrolytic graphite (PG) tiles and a lesser number of carbon fiber composite tiles are brazed. The small allowable tolerances for fitting the tiles to the tubes and mating of compound curvatures made the brazing and fabrication extremely challenging. The paper describes the fabrication process with emphasis on the procedure for brazing. In the fixturing for vacuum furnace brazing, the tiles were each independently clamped to the tube with an elaborate set of window frame clamps. Braze quality was evaluated with transient heating tests. Some rebrazing was necessary.

  19. ADA plaintiff must show AIDS limits major life activities.

    PubMed

    1998-05-15

    In a rare case, a Federal court ruled that AIDS does not automatically qualify a plaintiff for legal protection under the Americans with Disabilities Act (ADA). [Name removed], an Illinois Wal-Mart stock clerk, was fired weeks after telling the store's general manager of his HIV status. [Name removed] alleges that the firing was due solely to his disease. Wal-Mart contends that [name removed] was fired for sexually harassing a co-worker, and says that since [name removed] was asymptomatic and asked for no accommodations, he does not qualify for ADA protection. Magistrate Morton Denlow agreed, saying that [name removed] raised no genuine issues about whether the ADA should protect him. A trial is scheduled for May. PMID:11365337

  20. Absence of Remote Triggering in Geothermal Fields Due to Human Activity

    NASA Astrophysics Data System (ADS)

    Ge, S.; Zhang, Q.; Lin, G.

    2014-12-01

    Operational geothermal fields typically have high seismicity rates, which could be caused by both tectonic and anthropogenic activities. Due to the high background seismicity and possible interaction between fluid and seismic waves, geothermal areas have been recognized to be susceptible to large remote earthquakes. However, whether human activity (geothermal production) affects remote earthquake triggering by changing the stress state is unclear. Here we choose two geothermal fields, Coso and Salton Sea in southern California, to study the spatiotemporal distributions of the triggered earthquakes following the 1992 Mw 7.3 Landers and 1999 Mw 7.1 Hector Mine earthquakes. These two geothermal fields have been in operation since 1980s with comparable net capacity, and have long-term geothermal fluid loss. By analyzing the regional catalog recorded by the Southern California Seismic Network, we find that these two operational geothermal areas remain unaffected by the remote mainshocks, whereas the surrounding areas show vigorous triggered responses. We interpret this phenomenon as a result of human activity, which presumably has brought the stress state away from failure by reducing pore pressure. To further understand how much the human activity can affect the stress state, we also conduct a systematic study on Long Valley Caldera in northern California as a comparison site. Long Valley Caldera hosts an active geothermal field with net capacity about one sixth of that in Coso or Salton Sea geothermal field, and the extraction volume is not constantly larger than the injection. We will show comparisons of the triggered response in Long Valley with the two geothermal fields in southern California.

  1. Variations of 14C around AD 775 and AD 1795 - due to solar activity

    NASA Astrophysics Data System (ADS)

    Neuhäuser, R.; Neuhäuser, D. L.

    2015-12-01

    The motivation for our study is the disputed cause for the strong variation of 14C around AD 775. Our method is to compare the 14C variation around AD 775 with other periods of strong variability. Our results are: (a) We see three periods, where 14C varied over 200 yr in a special way showing a certain pattern of strong secular variation: after a Grand Minimum with strongly increasing 14C, there is a series of strong short-term drop(s), rise(s), and again drop(s) within 60 yr, ending up to 200 yr after the start of the Grand Minimum. These three periods include the strong rises around BC 671, AD 775, and AD 1795. (b) We show with several solar activity proxies (radioisotopes, sunspots, and aurorae) for the AD 770s and 1790s that such intense rapid 14C increases can be explained by strong rapid decreases in solar activity and, hence, wind, so that the decrease in solar modulation potential leads to an increase in radioisotope production. (c) The strong rises around AD 775 and 1795 are due to three effects, (i) very strong activity in the previous cycles (i.e. very low 14C level), (ii) the declining phase of a very strong Schwabe cycle, and (iii) a phase of very weak activity after the strong 14C rise - very short and/or weak cycle(s) like the suddenly starting Dalton minimum. (d) Furthermore, we can show that the strong change at AD 1795 happened after a pair of two packages of four Schwabe cycles with certain hemispheric leadership (each package consists of two Gnevyshev-Ohl pairs, respectively two Hale-Babcock pairs). We show with several additional arguments that the rise around AD 775 was not that special. We conclude that such large, short-term rises in 14C (around BC 671, AD 775, and 1795) do not need to be explained by highly unlikely solar super-flares nor other rare events, but by extra-solar cosmic rays modulated due to solar activity variations.

  2. Somatic Symptoms: Prevalence, Co-Occurrence and Associations with Self-Perceived Health and Limitations Due To Physical Health - A Danish Population-Based Study.

    PubMed

    Eliasen, Marie; Kreiner, Svend; Ebstrup, Jeanette F; Poulsen, Chalotte H; Lau, Cathrine J; Skovbjerg, Sine; Fink, Per K; Jørgensen, Torben

    2016-01-01

    A high number of somatic symptoms have been associated with poor health status and increased health care use. Previous studies focused on number of symptoms without considering the specific symptoms. The aim of the study was to investigate 1) the prevalence of 19 somatic symptoms, 2) the associations between the symptoms, and 3) the associations between the somatic symptoms, self-perceived health and limitations due to physical health accounting for the co-occurrence of symptoms. Information on 19 somatic symptoms, self-perceived health and limitations due to physical health was achieved from a population-based questionnaire survey of 36,163 randomly selected adults in the Capital Region of Denmark in 2006/07. Chain graph models were used to transparently identify and describe the associations between symptoms, self-perceived health and limitations due to physical health. In total, 94.9% of the respondents were bothered by one or more of the 19 somatic symptoms. The symptoms were associated in a complex structure. Still, recognisable patterns were identified within organ systems/body parts. When accounting for symptom co-occurrence; dizziness, pain in legs, respiratory distress and tiredness were all strongly directly associated with both of the outcomes (γ>0.30). Chest pain was strongly associated with self-perceived health, and other musculoskeletal symptoms and urinary retention were strongly associated with limitations due to physical health. Other symptoms were either moderate or not statistically associated with the health status outcomes. Opposite, almost all the symptoms were strongly associated with the two outcomes when not accounting for symptom co-occurrence. In conclusion, we found that somatic symptoms were frequent and associated in a complex structure. The associations between symptoms and health status measures differed between the symptoms and depended on the co-occurrence of symptoms. This indicates an importance of considering both the specific

  3. Endocannabinoids Control Platelet Activation and Limit Aggregate Formation under Flow

    PubMed Central

    De Angelis, Valentina; Koekman, Arnold C.; Weeterings, Cees; Roest, Mark; de Groot, Philip G.; Herczenik, Eszter; Maas, Coen

    2014-01-01

    Background The endocannabinoid system has previously been implicated in the regulation of neurons and inflammatory cells. Additionally, it has been reported that endocannabinoid receptors are present on circulating platelets, but there has been conflicting evidence on their contribution to platelet function. Objectives Our aim was to examine the role of endocannabinoids in platelet function in vitro and in vivo. Methods and Results We studied the effects of the well-characterized endogenous endocannabinoid anandamide on platelet aggregation in suspension, α-granule release, calcium mobilization, Syk phosphorylation, as well as platelet spreading and aggregate formation under flow. Anandamide inhibits platelet aggregation and α-granule release by collagen, collagen-derived peptide CRP-XL, ADP, arachidonic acid and thromboxane A2 analogue U46619. However, activation via thrombin receptor PAR-1 stays largely unaffected. Calcium mobilization is significantly impaired when platelets are stimulated with collagen or CRP-XL, but remains normal in the presence of the other agonists. In line with this finding, we found that anandamide prevents collagen-induced Syk phosphorylation. Furthermore, anandamide-treated platelets exhibit reduced spreading on immobilized fibrinogen, have a decreased capacity for binding fibrinogen in solution and show perturbed platelet aggregate formation under flow over collagen. Finally, we investigated the influence of Cannabis sativa consumption by human volunteers on platelet activation. Similar to our in vitro findings with anandamide, ex vivo collagen-induced platelet aggregation and aggregate formation on immobilized collagen under flow were impaired in whole blood of donors that had consumed Cannabis sativa. Conclusions Endocannabinoid receptor agonists reduce platelet activation and aggregate formation both in vitro and ex vivo after Cannabis sativa consumption. Further elucidation of this novel regulatory mechanism for platelet function

  4. Anti-inflammatory activity of roots of Cichorium intybus due to its inhibitory effect on various cytokines and antioxidant activity

    PubMed Central

    Rizvi, Waseem; Fayazuddin, Mohd.; Shariq, Syed; Singh, Ompal; Moin, Shagufta; Akhtar, Kafil; Kumar, Anil

    2014-01-01

    Background: Cichorium intybus L. commonly known as chicory is one of the important medicinal plants commonly used in Ayurvedic system of medicine. It is commonly used for the treatment of diseases involving a khapa and pitta doshas. Traditionally, C. intybus is used for the treatment of inflammatory conditions, but there are only few in vitro studies reporting the anti-inflammatory activity of roots of chicory. Objective: Evaluation of anti-inflammatory activity of roots of chicory and mechanisms involved in it using in vivo models of inflammation. Materials and Methods: Albino Wistar rats of either sex weighing 150–200 g were used. Ethanolic and aqueous extracts of roots of chicory were prepared with the help of Soxhlet's apparatus. The anti-inflammatory activity was studied using carrageenan-induced paw edema method and cotton pellet granuloma method. Levels of cytokines such as tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6), and IL-1 and activity of antioxidant enzymes such as catalase (CAT) and glutathione peroxidase (GPx) were estimated. Results: Chicory roots demonstrated significant dose-dependent decrease in paw edema in carrageenan-induced paw edema method. Chicory roots diminished the serum TNF-α, IL-6, and IL-1 levels. They also significantly attenuated the malonylaldehyde levels and increased the activities of CAT and GPx in paw tissue. Similarly, chicory roots demonstrated a significant decrease in granuloma formation in cotton pellet induced granuloma method. Conclusion: Chicory roots possess anti-inflammatory activity, and this might be due to the inhibition of various cytokines, antioxidant effects, and their free radical scavenging activity. PMID:25737610

  5. Anticancer drug released from near IR-activated prodrug overcomes spatiotemporal limits of singlet oxygen.

    PubMed

    Rajaputra, Pallavi; Bio, Moses; Nkepang, Gregory; Thapa, Pritam; Woo, Sukyung; You, Youngjae

    2016-04-01

    Photodynamic therapy (PDT) is a cancer treatment modality where photosensitizer (PS) is activated by visible and near IR light to produce singlet oxygen ((1)O2). However, (1)O2 has a short lifetime (<40 ns) and cannot diffuse (<20 nm) beyond the cell diameter (e.g., ∼ 1800 nm). Thus, (1)O2 damage is both spatially and temporally limited and does not produce bystander effect. In a heterogeneous tumor, cells escaping (1)O2 damage can regrow after PDT treatment. To overcome these limitations, we developed a prodrug concept (PS-L-D) composed of a photosensitizer (PS), an anti-cancer drug (D), and an (1)O2-cleavable linker (L). Upon illumination of the prodrug, (1)O2 is generated, which damages the tumor and also releases anticancer drug. The locally released drug could cause spatially broader and temporally sustained damage, killing the surviving cancer cells after the PDT damage. In our previous report, we presented the superior activity of our prodrug of CA4 (combretastatin A-4), Pc-(L-CA4)2, compared to its non-cleavable analog, Pc-(NCL-CA4)2, that produced only PDT effects. Here, we provide clear evidence demonstrating that the released anticancer drug, CA4, indeed damages the surviving cancer cells over and beyond the spatial and temporal limits of (1)O2. In the limited light illumination experiment, cells in the entire well were killed due to the effect of released anti-cancer drug, whereas only a partial damage was observed in the pseudo-prodrug treated wells. A time-dependent cell survival study showed more cell death in the prodrug-treated cells due to the sustained damage by the released CA4. Cell cycle analysis and microscopic imaging data demonstrated the typical damage patterns by CA4 in the prodrug treated cells. A time-dependent histological study showed that prodrug-treated tumors lacked mitotic bodies, and the prodrug caused broader and sustained tumor size reduction compared to those seen in the tumors treated with the pseudo-prodrug. This data

  6. TRADEOFFs in climate effects through aircraft routing: forcing due to radiatively active gases

    NASA Astrophysics Data System (ADS)

    Stordal, F.; Gauss, M.; Myhre, G.; Mancini, E.; Hauglustaine, D. A.; Köhler, M. O.; Berntsen, T.; . G Stordal, E. J.; Iachetti, D.; Pitari, G.; Isaksen, I. S. A.

    2006-10-01

    We have estimated impacts of alternative aviation routings on the radiative forcing. Changes in ozone and OH have been estimated in four Chemistry Transport Models (CTMs) participating in the TRADEOFF project. Radiative forcings due to ozone and methane have been calculated accordingly. In addition radiative forcing due to CO2 is estimated based on fuel consumption. Three alternative routing cases are investigated; one scenario assuming additional polar routes and two scenarios assuming aircraft cruising at higher (+2000 ft) and lower (-6000 ft) altitudes. Results from the base case in year 2000 are included as a reference. Taking first a steady state backward looking approach, adding the changes in the forcing from ozone, CO2 and CH4, the ranges of the models used in this work are -0.8 to -1.8 and 0.3 to 0.6 m Wm-2 in the lower (-6000 ft) and higher (+2000 ft) cruise levels, respectively. In relative terms, flying 6000ft lower reduces the forcing by 5-10% compared to the current flight pattern, whereas flying higher, while saving fuel and presumably flying time, increases the forcing by about 2-3%. Taking next a forward looking approach we have estimated the integrated forcing (m Wm-2 yr) over 20 and 100 years time horizons. The relative contributions from each of the three climate gases are somewhat different from the backward looking approach. The differences are moderate adopting 100 year time horizon, whereas under the 20 year horizon CO2 naturally becomes less important relatively. Thus the forcing agents impact climate differently on various time scales. Also, we have found significant differences between the models for ozone and methane. We conclude that we are not yet at a point where we can include non-CO2 effects of aviation in emission trading schemes. Nevertheless, the rerouting cases that have been studied here yield relatively small changes in the radiative forcing due to the radiatively active gases.

  7. Undesirable Consequences of Insecticide Resistance following Aedes aegypti Control Activities Due to a Dengue Outbreak

    PubMed Central

    Maciel-de-Freitas, Rafael; Avendanho, Fernando Campos; Santos, Rosangela; Sylvestre, Gabriel; Araújo, Simone Costa; Lima, José Bento Pereira; Martins, Ademir Jesus; Coelho, Giovanini Evelim; Valle, Denise

    2014-01-01

    Background During a dengue outbreak with co-circulation of DENV-1 and -2 in the city of Boa Vista, one patient was diagnosed with DENV-4, a serotype supposed absent from Brazil for almost 30 years. The re-emergence of DENV-4 triggered the intensification of mechanical and chemical Aedes aegypti control activities in order to reduce vector density and avoid DENV-4 dissemination throughout the country. Methods/Principal Findings Vector control activities consisted of (a) source reduction, (b) application of diflubenzuron against larvae and (c) vehicle-mounted space spraying of 2% deltamethrin to eliminate adults. Control activity efficacy was monitored by comparing the infestation levels and the number of eggs collected in ovitraps before and after interventions, performed in 22 Boa Vista districts, covering an area of ∼80% of the city and encompassing 56,837 dwellings. A total of 94,325 containers were eliminated or treated with diflubenzuron. The most frequently positive containers were small miscellaneous receptacles, which corresponded to 59% of all positive breeding sites. Insecticide resistance to deltamethrin was assessed before, during and after interventions by dose-response bioassays adopting WHO-based protocols. The intense use of the pyrethroid increased fourfold the resistance ratio of the local Ae. aegypti population only six months after the beginning of vector control. Curiously, this trend was also observed in the districts in which no deltamethrin was applied by the public health services. On the other hand, changes in the resistance ratio to the organophosphate temephos seemed less influenced by insecticide in Boa Vista. Conclusions Despite the intense effort, mosquito infestation levels were only slightly reduced. Besides, the median number of eggs in ovitraps remained unaltered after control activity intensification. The great and rapid increase in pyrethroid resistance levels of natural Ae. aegypti populations is discussed in the context of

  8. Measuring Activity Limitation Outcomes in Youth with Spinal Cord Injury

    PubMed Central

    Slavin, Mary D.; Mulcahey, MJ; Calhoun, Christina; Ni, Pengsheng; Vogel, Lawrence C.; Haley, Stephen M.; Jette, Alan M.

    2016-01-01

    Study Design Cross-sectional Objectives The Pediatric Spinal Cord Injury Activity Measure (PEDI-SCI AM), which includes calibrated item banks (child and parent versions) for General Mobility, Daily Routines, Wheeled Mobility and Ambulation, can be administered using computerized adaptive tests (CATs) or short forms (SFs). The study objectives are: 1.) examine the psychometric properties of the PEDISCI AM item banks and 10-item CATs); 2.) develop and evaluate the psychometric properties of PEDI-SCI AM SFs. Setting U.S. Shriners Hospitals for Children (California, Illinois and Pennsylvania). Methods Calibration data from a convenience sample of 381 children and adolescents with SCI and 322 parents or caregivers were used to examine PEDI-SCI AM item banks, 10-item CATs and SF scores. We calculated group reliability, internal consistency (Cronbach's alpha), and interclass coefficients (ICCs) to assess agreement between 10-item CATs, SFs and item banks. The percent of the sample with highest (ceiling) and lowest (floor) scores was also determined. An expert panel selected items for 14 SFs. Results PEDI-SCI item banks, 10-item CATs and SFs demonstrate acceptable group reliability (0.73-0.96) and internal consistency (0.77-0.98). ICC values show strong agreement with item banks for 10-item CATs (0.72-0.99) and SFs. Floor effects are minimal (<15%). Ceiling effects are minimal for children with tetraplegia, but high in children with paraplegia for General Mobility (13.41-26.05%) and Daily Activities (12.99-32.71%). Conclusions The PEDI-SCI AM exhibited strong psychometric properties for children with tetraplegia. Replenishment of the General Mobility and Daily Routines item banks is needed to reduce ceiling effects noted for youth with paraplegia. PMID:26572606

  9. 12 CFR 980.2 - Limitation on Bank authority to undertake new business activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... business activities. 980.2 Section 980.2 Banks and Banking FEDERAL HOUSING FINANCE BOARD NEW FEDERAL HOME LOAN BANK ACTIVITIES NEW BUSINESS ACTIVITIES § 980.2 Limitation on Bank authority to undertake new business activities. No Bank shall undertake any new business activity except in accordance with...

  10. Depletion of NADP(H) due to CD38 activation triggers endothelial dysfunction in the postischemic heart.

    PubMed

    Reyes, Levy A; Boslett, James; Varadharaj, Saradhadevi; De Pascali, Francesco; Hemann, Craig; Druhan, Lawrence J; Ambrosio, Giuseppe; El-Mahdy, Mohamed; Zweier, Jay L

    2015-09-15

    In the postischemic heart, coronary vasodilation is impaired due to loss of endothelial nitric oxide synthase (eNOS) function. Although the eNOS cofactor tetrahydrobiopterin (BH4) is depleted, its repletion only partially restores eNOS-mediated coronary vasodilation, indicating that other critical factors trigger endothelial dysfunction. Therefore, studies were performed to characterize the unidentified factor(s) that trigger endothelial dysfunction in the postischemic heart. We observed that depletion of the eNOS substrate NADPH occurs in the postischemic heart with near total depletion from the endothelium, triggering impaired eNOS function and limiting BH4 rescue through NADPH-dependent salvage pathways. In isolated rat hearts subjected to 30 min of ischemia and reperfusion (I/R), depletion of the NADP(H) pool occurred and was most marked in the endothelium, with >85% depletion. Repletion of NADPH after I/R increased NOS-dependent coronary flow well above that with BH4 alone. With combined NADPH and BH4 repletion, full restoration of NOS-dependent coronary flow occurred. Profound endothelial NADPH depletion was identified to be due to marked activation of the NAD(P)ase-activity of CD38 and could be prevented by inhibition or specific knockdown of this protein. Depletion of the NADPH precursor, NADP(+), coincided with formation of 2'-phospho-ADP ribose, a CD38-derived signaling molecule. Inhibition of CD38 prevented NADP(H) depletion and preserved endothelium-dependent relaxation and NO generation with increased recovery of contractile function and decreased infarction in the postischemic heart. Thus, CD38 activation is an important cause of postischemic endothelial dysfunction and presents a novel therapeutic target for prevention of this dysfunction in unstable coronary syndromes.

  11. The nucleoporin Nup153 affects spindle checkpoint activity due to an association with Mad1

    PubMed Central

    Shimi, Takeshi

    2010-01-01

    The nucleoporin Nup153 is known to play pivotal roles in nuclear import and export in interphase cells and as the cell transitions into mitosis, Nup153 is involved in nuclear envelope breakdown. In this study, we demonstrate that the interaction of Nup153 with the spindle assembly checkpoint protein Mad1 is important in the regulation of the spindle checkpoint. Overexpression of human Nup153 in HeLa cells leads to the appearance of multinucleated cells and induces the formation of multipolar spindles. Importantly, it causes inactivation of the spindle checkpoint due to hypophosphorylation of Mad1. Depletion of Nup153 using RNA interference results in the decline of Mad1 at nuclear pores during interphase and more significantly causes a delayed dissociation of Mad1 from kinetochores in metaphase and an increase in the number of unresolved midbodies. In the absence of Nup153 the spindle checkpoint remains active. In vitro studies indicate direct binding of Mad1 to the N-terminal domain of Nup153. Importantly, Nup153 binding to Mad1 affects Mad1's phosphorylation status, but not its ability to interact with Mad2. Our data suggest that Nup153 levels regulate the localization of Mad1 during the metaphase/anaphase transition thereby affecting its phoshorylation status and in turn spindle checkpoint activity and mitotic exit. PMID:21327106

  12. Dynamic instability of cooperation due to diverse activity patterns in evolutionary social dilemmas

    NASA Astrophysics Data System (ADS)

    Xia, Cheng-Yi; Meloni, Sandro; Perc, Matjaž; Moreno, Yamir

    2015-03-01

    Individuals might abstain from participating in an instance of an evolutionary game for various reasons, ranging from lack of interest to risk aversion. In order to understand the consequences of such diverse activity patterns on the evolution of cooperation, we study a weak prisoner's dilemma where each player's participation is probabilistic rather than certain. Players that do not participate get a null payoff and are unable to replicate. We show that inactivity introduces cascading failures of cooperation, which are particularly severe on scale-free networks with frequently inactive hubs. The drops in the fraction of cooperators are sudden, while the spatiotemporal reorganization of compact cooperative clusters, and thus the recovery, takes time. Nevertheless, if the activity of players is directly proportional to their degree, or if the interaction network is not strongly heterogeneous, the overall evolution of cooperation is not impaired. This is because inactivity negatively affects the potency of low-degree defectors, who are hence unable to utilize on their inherent evolutionary advantage. Between cascading failures, the fraction of cooperators is therefore higher than usual, which lastly balances out the asymmetric dynamic instabilities that emerge due to intermittent blackouts of cooperative hubs.

  13. Whiting events: biogenic origin due to the photosynthetic activity of cyanobacterial picoplankton

    NASA Technical Reports Server (NTRS)

    Thompson, J. B.; Schultze-Lam, S.; Beveridge, T. J.; Des Marais, D. J.

    1997-01-01

    An annual whiting event occurs each year in late May to early June in Fayetteville Green Lake, New York. The initiation of this event correlates with exponential growth of the Synechococcus population within the lake. Synechococcus is the dominant (by approximately 4 orders of magnitude) autotrophic organism owing to the oligotrophic condition of the lake. The delta 13C values of the dissolved inorganic C range seasonally from -9.5% in winter to -6.2% in summer due to photosynthetic activity. Calcite precipitates principally in the microenvironment surrounding Synechococcus because of a photosynthetically driven alkalization process and the availability of the cells as nucleation sites. This calcite has a heavier delta 13C value (>4%) than does the dissolved inorganic C of the lake water owing to the cells' preferential uptake of 12C. A conceptual model suggests that photosynthetic activity and cell surface chemistry, together with the substantial surface area that arises from the great abundance of micron-sized cells, allow Synechococcus to dominate the annual whiting events in Fayetteville Green Lake.

  14. Effect of structured physical activity on respiratory outcomes in sedentary elderly adults with mobility limitations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    OBJECTIVES: To evaluate the effect of structured physical activity on respiratory outcomes in community dwelling elderly adults with mobility limitations. DESIGN: Multicenter, randomized trial of physical activity vs health education, with respiratory variables prespecified as tertiary outcomes over...

  15. IMPLICATIONS OF MASS AND ENERGY LOSS DUE TO CORONAL MASS EJECTIONS ON MAGNETICALLY ACTIVE STARS

    SciTech Connect

    Drake, Jeremy J.; Cohen, Ofer; Yashiro, Seiji; Gopalswamy, Nat

    2013-02-20

    Analysis of a database of solar coronal mass ejections (CMEs) and associated flares over the period 1996-2007 finds well-behaved power-law relationships between the 1-8 A flare X-ray fluence and CME mass and kinetic energy. We extrapolate these relationships to lower and higher flare energies to estimate the mass and energy loss due to CMEs from stellar coronae, assuming that the observed X-ray emission of the latter is dominated by flares with a frequency as a function of energy dn/dE = kE {sup -{alpha}}. For solar-like stars at saturated levels of X-ray activity, the implied losses depend fairly weakly on the assumed value of {alpha} and are very large: M-dot {approx}5 Multiplication-Sign 10{sup -10} M{sub sun} yr{sup -1} and E-dot {approx}0.1 L{sub sun}. In order to avoid such large energy requirements, either the relationships between CME mass and speed and flare energy must flatten for X-ray fluence {approx}> 10{sup 31} erg, or the flare-CME association must drop significantly below 1 for more energetic events. If active coronae are dominated by flares, then the total coronal energy budget is likely to be up to an order of magnitude larger than the canonical 10{sup -3} L {sub bol} X-ray saturation threshold. This raises the question of what is the maximum energy a magnetic dynamo can extract from a star? For an energy budget of 1% of L {sub bol}, the CME mass loss rate is about 5 Multiplication-Sign 10{sup -11} M {sub Sun} yr{sup -1}.

  16. Learning Needs and Activity Limitations of Elderly Japanese with Physical Disabilities.

    ERIC Educational Resources Information Center

    Hori, Shigeo; Fujiwara, Mizuho

    2003-01-01

    A survey of 364 Japanese adults over 60 with physical disabilities found that 87% have learning needs in the areas of health care, communication, and leisure activities. Instrumental/social learning ranked higher among those with serious activity limitations. Expressive/communicative learning was more important for those with moderate limitations.…

  17. A Hands-On Activity Incorporating the Threefold Representation on Limiting Reactant

    ERIC Educational Resources Information Center

    Gonza´lez-Sa´nchez, Ange´lica M.; Ortiz-Nieves, Edgardo L.; Medina, Zuleikra

    2014-01-01

    Many students share the common belief that the limiting reactant in a chemical reaction is the reactant in the smallest quantity of material. To help students overcome this difficulty a hands-on activity for the limiting reactant concept was developed. The activity incorporates the three levels of representation (macroscopic, submicroscopic, and…

  18. 26 CFR 1.103(n)-3T - Private activity bond limit (temporary).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 26 Internal Revenue 2 2011-04-01 2011-04-01 false Private activity bond limit (temporary). 1.103(n)-3T Section 1.103(n)-3T Internal Revenue INTERNAL REVENUE SERVICE, DEPARTMENT OF THE TREASURY....103(n)-3T Private activity bond limit (temporary). Q-1: What is the “State ceiling”? A-1: In...

  19. Response of the turbidity maximum zone in the Yangtze River Estuary due to human activities during the dry season.

    PubMed

    Chen, Xiaofeng; Shen, Zhenyao; Yang, Ye

    2016-09-01

    The interaction between a river and the sea results in a turbidity maximum zone (TMZ) within the estuary, which has a great impact on the local ecosystem. In the Yangtze River Estuary, the magnitude and extent of the TMZ vary with water discharge. In this study, the cumulative human activity altered the water discharge regime from the river to the estuary. In the post-Three Gorges Dam (TGD) period, water discharge increased by 35.10 % at Datong in February compared with that in the pre-TGD period. The effects of water discharge variation on the characteristics of the TMZ were analyzed during spring and neap tidal periods using the three-dimensional environmental fluid dynamic code (EFDC) model. The area of the TMZ decreased by 3.11 and 17.39 % during neap and spring tides, respectively. In addition, the upper limit of the TMZ moved 11.68 km seaward during neap tide, whereas the upper limit of the TMZ in the upstream and downstream areas moved seaward 9.65 and 2.34 km, respectively, during spring tide. These findings suggest that the area and location of the TMZ are more sensitive to upstream runoff during spring tide than during neap tide. These changes in the TMZ will impact the biochemical processes in the Yangtze River Estuary. In the foreseeable future, the distribution characteristic of TMZ will inevitably change due to variations in the Yangtze River discharge resulting from new human activities (i.e., new dams), which are being constructed upstream in the Yangtze River system.

  20. Response of the turbidity maximum zone in the Yangtze River Estuary due to human activities during the dry season.

    PubMed

    Chen, Xiaofeng; Shen, Zhenyao; Yang, Ye

    2016-09-01

    The interaction between a river and the sea results in a turbidity maximum zone (TMZ) within the estuary, which has a great impact on the local ecosystem. In the Yangtze River Estuary, the magnitude and extent of the TMZ vary with water discharge. In this study, the cumulative human activity altered the water discharge regime from the river to the estuary. In the post-Three Gorges Dam (TGD) period, water discharge increased by 35.10 % at Datong in February compared with that in the pre-TGD period. The effects of water discharge variation on the characteristics of the TMZ were analyzed during spring and neap tidal periods using the three-dimensional environmental fluid dynamic code (EFDC) model. The area of the TMZ decreased by 3.11 and 17.39 % during neap and spring tides, respectively. In addition, the upper limit of the TMZ moved 11.68 km seaward during neap tide, whereas the upper limit of the TMZ in the upstream and downstream areas moved seaward 9.65 and 2.34 km, respectively, during spring tide. These findings suggest that the area and location of the TMZ are more sensitive to upstream runoff during spring tide than during neap tide. These changes in the TMZ will impact the biochemical processes in the Yangtze River Estuary. In the foreseeable future, the distribution characteristic of TMZ will inevitably change due to variations in the Yangtze River discharge resulting from new human activities (i.e., new dams), which are being constructed upstream in the Yangtze River system. PMID:27287491

  1. A review on soil carbon accumulation due to the management change of major Brazilian agricultural activities.

    PubMed

    La Scala jr, N; De Figueiredo, E B; Panosso, A R

    2012-08-01

    Agricultural areas deal with enormous CO2 intake fluxes offering an opportunity for greenhouse effect mitigation. In this work we studied the potential of soil carbon sequestration due to the management conversion in major agricultural activities in Brazil. Data from several studies indicate that in soybean/maize, and related rotation systems, a significant soil carbon sequestration was observed over the year of conversion from conventional to no-till practices, with a mean rate of 0.41 Mg C ha(-1) year(-1). The same effect was observed in sugarcane fields, but with a much higher accumulation of carbon in soil stocks, when sugarcane fields are converted from burned to mechanised based harvest, where large amounts of sugarcane residues remain on the soil surface (1.8 Mg C ha(-1) year(-1)). The higher sequestration potential of sugarcane crops, when compared to the others, has a direct relation to the primary production of this crop. Nevertheless, much of this mitigation potential of soil carbon accumulation in sugarcane fields is lost once areas are reformed, or intensive tillage is applied. Pasture lands have shown soil carbon depletion once natural areas are converted to livestock use, while integration of those areas with agriculture use has shown an improvement in soil carbon stocks. Those works have shown that the main crop systems of Brazil have a huge mitigation potential, especially in soil carbon form, being an opportunity for future mitigation strategies.

  2. The mesoscale sediment transport due to technical activities in the deep sea

    NASA Astrophysics Data System (ADS)

    Jankowski, Jacek A.; Zielke, Werner

    This paper presents a mesoscale model for sediment transport in the deep sea resulting from technical activities such as manganese nodule mining. The model includes the temporal variability of ambient currents, the modification of the water density due to suspended sediments (density driven flow), bottom boundary-layer effects, and the influence of flocculation on the sediment settling velocity. It yields the three-dimensional sediment concentration and the bottom blanketing for time periods of up to a few weeks in areas of up to a few hundred square kilometers. The model also allows simulation of the mobilization, sorption and the transport of heavy metals. Two applications are presented. One treats the sediment transport during the NOAA Benthic Impact Experiment. The other is concerned with dispersion of heavy metals, including the interaction with suspended sediment in the Disturbance and Recolonization Experiment Experimental Area. The model is highly sophisticated with regard to the processes and numerical methods. Nevertheless, a final conclusion concerning the quantification of its prognostic capability for industrial scale operations cannot presently be drawn because of the lack of complete and coherent data sets.

  3. Production of synthetic methionine-free and synthetic methionine-limited alpha casein: protein foodstuff for patients with homocystinuria due to cystathionine beta-synthase deficiency.

    PubMed

    Goda, Sayed K; Abu Aqel, Yasmin W; Al-Aswad, Mai R; Rashedy, Fatma A B; Mohamed, Amr S

    2010-01-01

    The aim of this study was to evaluate the possibility that synthetic forms of methionine-free alpha-casein and methionine-limited alpha casein could be produced by recombinant means to form the basis for developing an industrial-scale process for the provision of a foodstuff suitable for patients with homocystinuria due to cystathionine beta-synthase (CBS) deficiency. As a first step, two forms of alpha casein gene, encoding methionine-free alpha casein (Fcas) or a methionine-limited alpha casein (Mcas), were synthesised and expressed in Escherichia coli. Using the overexpression vector pET28a, both genes were highly expressed in E. coli in soluble form as well as in inclusion bodies. The two recombinant proteins were purified by the one step methods using the fused His-tag and the Ni(2+)column and validated by Western blot analysis. This work paves the way for industrial-scale production of proteins suitable for patients with homocystinuria due to CBS deficiency.

  4. Elevated Ground Temperatures at Crude Oil Spill Sites due to Microbial Activity

    NASA Astrophysics Data System (ADS)

    Warren, E.; Bekins, B. A.

    2009-12-01

    Crude oil near the water table at spill sites near Bemidji and Cass Lake, Minnesota, has been undergoing aerobic and anaerobic biodegradation for decades. Because the reactions are exothermic, biodegradation of oil compounds will produce measurable temperature increases if heat is generated faster than it is transported away from the oil body. Subsurface temperatures at the two spill sites were measured with thermistors at multiple depths in groundwater monitoring wells and water-filled tubes in the vadose zone. Temperatures in selected wells were measured in the summer of 2007, 2008, and 2009. At the Bemidji site, temperatures measured in the summer ranged from a low of 6.3 oC in the background well to a high of 9.2 oC within wells in the oil-contaminated zone. From year to year, background minimum temperatures were constant within +/- 0.05 oC while maximum temperatures within the oil-contaminated zone remained within +/- 0.25 oC. Seasonal changes in temperature in the plume as measured by data loggers exceeded 4 oC, which was far greater than the year to year change in the summer measurements. Seasonal variability was greater near the water table than at depth. It is unclear whether this variability is due to subsurface hydrology or microbial activity. Temperatures in the vadose zone were warmer near and down-gradient from the oil body compared to the background indicating the heat from the oil and plume propagates up and outward into the vadose zone. At the Cass Lake site, summer temperatures in 2009 were 6.4 oC in the background and 11.5 oC in wells near the oil. Reaction rates inferred from chemical data were compared to heating required in a 3-dimension energy transport model of the subsurface. The increased temperature compared well to the expected heat production from biodegradation reactions occurring in the oil and plume. Results indicate that microbial activity in sediments contaminated with crude oil undergoing biodegradation can be detected using

  5. Airway Tissue Plasminogen Activator Prevents Acute Mortality Due to Lethal Sulfur Mustard Inhalation

    PubMed Central

    Veress, Livia A.; Anderson, Dana R.; Hendry-Hofer, Tara B.; Houin, Paul R.; Rioux, Jacqueline S.; Garlick, Rhonda B.; Loader, Joan E.; Paradiso, Danielle C.; Smith, Russell W.; Rancourt, Raymond C.; Holmes, Wesley W.; White, Carl W.

    2015-01-01

    Rationale: Sulfur mustard (SM) is a chemical weapon stockpiled today in volatile regions of the world. SM inhalation causes a life-threatening airway injury characterized by airway obstruction from fibrin casts, which can lead to respiratory failure and death. Mortality in those requiring intubation is more than 80%. No therapy exists to prevent mortality after SM exposure. Our previous work using the less toxic analog of SM, 2-chloroethyl ethyl sulfide, identified tissue plasminogen activator (tPA) an effective rescue therapy for airway cast obstruction (Veress, L. A., Hendry-Hofer, T. B., Loader, J. E., Rioux, J. S., Garlick, R. B., and White, C. W. (2013). Tissue plasminogen activator prevents mortality from sulfur mustard analog-induced airway obstruction. Am. J. Respir. Cell Mol. Biol. 48, 439–447). It is not known if exposure to neat SM vapor, the primary agent used in chemical warfare, will also cause death due to airway casts, and if tPA could be used to improve outcome. Methods: Adult rats were exposed to SM, and when oxygen saturation reached less than 85% (median: 6.5 h), intratracheal tPA or placebo was given under isoflurane anesthesia every 4 h for 48 h. Oxygen saturation, clinical distress, and arterial blood gases were assessed. Microdissection was done to assess airway obstruction by casts. Results: Intratracheal tPA treatment eliminated mortality (0% at 48 h) and greatly improved morbidity after lethal SM inhalation (100% death in controls). tPA normalized SM-associated hypoxemia, hypercarbia, and lactic acidosis, and improved respiratory distress. Moreover, tPA treatment resulted in greatly diminished airway casts, preventing respiratory failure from airway obstruction. Conclusions: tPA given via airway more than 6 h after exposure prevented death from lethal SM inhalation, and normalized oxygenation and ventilation defects, thereby rescuing from respiratory distress and failure. Intra-airway tPA should be considered as a life

  6. In Vivo Activity of Ceftobiprole in Murine Skin Infections Due to Staphylococcus aureus and Pseudomonas aeruginosa▿

    PubMed Central

    Fernandez, Jeffrey; Hilliard, Jamese J.; Abbanat, Darren; Zhang, Wenyan; Melton, John L.; Santoro, Colleen M.; Flamm, Robert K.; Bush, Karen

    2010-01-01

    Ceftobiprole, a broad-spectrum cephalosporin with activity against methicillin-resistant Staphylococcus aureus (MRSA) (P. Hebeisen et al., Antimicrob. Agents Chemother. 45:825-836, 2001), was evaluated in a subcutaneous skin infection model with Staphylococcus aureus Smith OC 4172 (methicillin-susceptible S. aureus [MSSA]), S. aureus OC 8525 (MRSA), Pseudomonas aeruginosa OC 4351 (having an inducible AmpC β-lactamase), and P. aeruginosa OC 4354 (overproducing AmpC β-lactamase). In the MSSA and MRSA infection models, ceftobiprole, administered as the prodrug ceftobiprole medocaril, was more effective in reducing CFU/g skin (P < 0.001) than were cefazolin, vancomycin, or linezolid based on the dose-response profiles. Skin lesion volumes in MSSA-infected animals treated with ceftobiprole were 19 to 29% lower than those for cefazolin-, vancomycin-, or linezolid-treated animals (P < 0.001). In MRSA infections, lesion size in ceftobiprole-treated mice was 34% less than that with cefazolin or linezolid treatment (P < 0.001). Against P. aeruginosa, ceftobiprole at similar doses was as effective as meropenem-cilastatin in reductions of CFU/g skin, despite 8- and 32-fold-lower MICs for meropenem; both treatments were more effective than was cefepime (P < 0.001) against the inducible and overproducing AmpC β-lactamase strains of P. aeruginosa. Ceftobiprole was similar to meropenem-cilastatin and 47 to 54% more effective than cefepime (P < 0.01) in reducing the size of the lesion caused by either strain of P. aeruginosa in this study. These studies indicate that ceftobiprole is effective in reducing both bacterial load and lesion volume associated with infections due to MSSA, MRSA, and P. aeruginosa in this murine model of skin and soft tissue infection. PMID:19884364

  7. Imbalance of Nature due to Anthropogenic Activities in the Bay of Bacorehuis, Sinaloa, Mexico

    NASA Astrophysics Data System (ADS)

    Torrecillas Nunez, C.; Cárdenas Cota, H.

    2013-05-01

    Pollution is further enhancing water scarcity by reducing water usability downstream, globally the most prevalent water quality problem is eutrophication, a result of high-nutrient loads, which substantially impairs beneficial uses of water. Projected food production needs and increasing wastewater effluents associated with an increasing population over the next three decades suggest a 10%-15% increase in the river input of nitrogen loads into coastal ecosystems (UNO, 2009). Our study in the Bay of Bacorehuis in the State of Sinaloa, which was carried out due to a request from local fishermen who wanted to find out the reason for fishing stocks depletion, confirmed this trend with the consequent imbalance of nature. Sinaloa depends heavily on intensive agricultural production to support its economy which in turn relies on water irrigation and the application of agro-chemicals. The research project included a desk top study of geophysical and environmental factors as well as sampling and testing of the water. In addition we carried out socio-economic research to find out the impact on the local community of the imbalance caused by anthropogenic activities in the watershed upstream from the Bay. Our research established that the Bay of Bacorehuis is contaminated by organic matter, bacteria coliforms, pesticides and mercury due to the discharge of surplus runoff generated by irrigation of farmlands into drainage networks as well as the discharge of untreated industrial and domestic wastewater form more than 24,000 inhabitants. The main contaminants detected in the water bodies were organic matter, faecal coliforms, mercury, dimethoate, endosulfan, heptachlor, DDE, DDT, organonitrogen, synthetic pyrethroid, chlorothalonil, ethion, endosulfan, diazinon, malathion and chlorpyrifos. Contaminants in sediments included the pesticides endosulfan, heptachlor, DDE, DDT, organophosphates, organonitrogen and synthetic pyrethroids. Natural water courses have been highly modified

  8. Relevance of watershed modelling to assess the contamination of coastal waters due to land-based sources and activities

    NASA Astrophysics Data System (ADS)

    Rollo, Nicolas; Robin, Marc

    2010-02-01

    To evaluate the relevance of a watershed modelling for assessing the contamination of coastal waters due to land-based sources and activities, a modelling approach, using SWAT (Soil and Water Assessment Tool) model, was implemented on the watersheds of Pen-Bé estuary and Le Croisic bay. For the past few years, various dysfunctions occurred in these shellfish farming areas located on the West coast of France. Therefore, it seemed critical to estimate the coastal watershed loadings in order to get a better understanding of the dysfunctions. In the same way, an empiric method based on water quality samplings was also carried out in order to evaluate the potential pollutant attenuation of the coastal wetlands. The results presented in this paper focus on simulated streamflows and phosphorus flows. Despite the limited existing data, which involved to integrate aggregated or averaged values for several aspects, according to the Nash and Sutcliffe efficiency criterion, the simulated flows seem close to the measurements. The simulated continuous flows appeared as a useful complement to intermittent water quality samplings and streamflow measures resulting from water monitoring networks. Moreover, by identifying the most contributory sub-watersheds, the simulations could be used to suggest priority areas of intervention for decreasing the coastal watershed loadings.

  9. Experimental response of Salix cuttings to different flow regimes due to human activities

    NASA Astrophysics Data System (ADS)

    Gorla, Lorenzo; Signarbieux, Constant; Turberg, Pascal; Buttler, Alexandre; Perona, Paolo

    2014-05-01

    Hydropower production and other human activities change the natural flow regime of rivers, in turn impacting the riparian environment. The main challenge in order to define eco-sustainable flows is to quantify the effects in terms of geomorphology and ecosystem adaptation. We present 2-years controlled experiments to investigate riparian vegetation (Salix Viminalis) response to forced water table changing dynamics, from one water regime to another, in a temperate region (Switzerland). Three synthetic flow regimes have been simulated and applied to three batteries of Salix cuttings growing outdoor within plastic pots, each about 1 meter tall. In 2012 one treatment simulated a minimal flow policy for small run-of-river hydropower plants, which drastically impacts the low and the medium-low components of the hydrograph, but not the extremes. In 2013 we confirmed and completed some of 2012 results, by reproducing typical hydropeaking effects due to dam management and focusing on daily water table variations and offsets. For both the seasons, after an initial period where all pots undergone the same oscillations in order to uniform the plants initial conditions, the experiment started, and the water dynamic was changed. Cuttings transitory response dynamics has been quantified by continuous sap flow and water potential measurements, and by regularly collecting growth parameters, as well as leaves photosynthesis, fluorescence, and pictures of each plant. At the end of the experiment, all cuttings were carefully removed and the both above and below ground biomass analyzed in detail. Particularly, the 3D root structure was obtained by High Resolution Computer Tomography. Our analyses revealed a clear dependence between roots distribution and water regime reflecting the need for adaptation, in agreement with field observations of Pasquale et al. (2012). In particular, an initial strong difference in terms of stress and growth performances was then followed by a later

  10. The Limit of Magnetic-Shear Energy in Solar Active Regions

    NASA Technical Reports Server (NTRS)

    Moore, Ronald L.; Falconer, David A.; Sterling, Alphonse C.

    2013-01-01

    It has been found previously, by measuring from active ]region magnetograms a proxy of the free energy in the active region fs magnetic field, (1) that there is a sharp upper limit to the free energy the field can hold that increases with the amount of magnetic field in the active region, the active region fs magnetic flux content, and (2) that most active regions are near this limit when their field explodes in a CME/flare eruption. That is, explosive active regions are concentrated in a main ]sequence path bordering the free ]energy ]limit line in (flux content, free ]energy proxy) phase space. Here we present evidence that specifies the underlying magnetic condition that gives rise to the free ]energy limit and the accompanying main sequence of explosive active regions. Using a suitable free energy proxy measured from vector magnetograms of 44 active regions, we find evidence that (1) in active regions at and near their free ]energy limit, the ratio of magnetic ]shear free energy to the non ]free magnetic energy the potential field would have is of order 1 in the core field, the field rooted along the neutral line, and (2) this ratio is progressively less in active regions progressively farther below their free ]energy limit. Evidently, most active regions in which this core ]field energy ratio is much less than 1 cannot be triggered to explode; as this ratio approaches 1, most active regions become capable of exploding; and when this ratio is 1, most active regions are compelled to explode.

  11. The Limit of Magnetic-Shear Energy in Solar Active Regions

    NASA Technical Reports Server (NTRS)

    Moore, Ronald; Falconer, David; Sterling, Alphonse

    2012-01-01

    It has been found previously, by measuring from active-region magnetograms a proxy of the free energy in the active region's magnetic field, (1) that there is a sharp upper limit to the free energy the field can hold that increases with the amount of magnetic field in the active region, the active region's magnetic flux content, and (2) that most active regions are near this limit when their field explodes in a coronal mass ejection/flare eruption. That is, explosive active regions are concentrated in a main-sequence path bordering the free-energy-limit line in (flux content, free-energy proxy) phase space. Here, we present evidence that specifies the underlying magnetic condition that gives rise to the free-energy limit and the accompanying main sequence of explosive active regions. Using a suitable free-energy proxy measured from vector magnetograms of 44 active regions, we find evidence that (1) in active regions at and near their free-energy limit, the ratio of magnetic-shear free energy to the non-free magnetic energy the potential field would have is of the order of one in the core field, the field rooted along the neutral line, and (2) this ratio is progressively less in active regions progressively farther below their free-energy limit. Evidently, most active regions in which this core-field energy ratio is much less than one cannot be triggered to explode; as this ratio approaches one, most active regions become capable of exploding; and when this ratio is one, most active regions are compelled to explode.

  12. THE LIMIT OF MAGNETIC-SHEAR ENERGY IN SOLAR ACTIVE REGIONS

    SciTech Connect

    Moore, Ronald L.; Falconer, David A.; Sterling, Alphonse C.

    2012-05-01

    It has been found previously, by measuring from active-region magnetograms a proxy of the free energy in the active region's magnetic field, (1) that there is a sharp upper limit to the free energy the field can hold that increases with the amount of magnetic field in the active region, the active region's magnetic flux content, and (2) that most active regions are near this limit when their field explodes in a coronal mass ejection/flare eruption. That is, explosive active regions are concentrated in a main-sequence path bordering the free-energy-limit line in (flux content, free-energy proxy) phase space. Here, we present evidence that specifies the underlying magnetic condition that gives rise to the free-energy limit and the accompanying main sequence of explosive active regions. Using a suitable free-energy proxy measured from vector magnetograms of 44 active regions, we find evidence that (1) in active regions at and near their free-energy limit, the ratio of magnetic-shear free energy to the non-free magnetic energy the potential field would have is of the order of one in the core field, the field rooted along the neutral line, and (2) this ratio is progressively less in active regions progressively farther below their free-energy limit. Evidently, most active regions in which this core-field energy ratio is much less than one cannot be triggered to explode; as this ratio approaches one, most active regions become capable of exploding; and when this ratio is one, most active regions are compelled to explode.

  13. A population-based profile of adult Canadians living with participation and activity limitations

    PubMed Central

    Goodridge, Donna; Lawson, Josh; Marciniuk, Darcy; Rennie, Donna

    2011-01-01

    Background: Currently, one out of every seven Canadians is affected by limitations to their participation and activity. This study describes the self-reported main causes of these limitations in a national sample. Methods: The 2006 Participation and Activity Limitation Survey was a two-phase stratified survey based on filter questions posed in the 2006 Census of Population conducted by Statistics Canada. Respondents to the survey represent 5 185 980 Canadian adults with activity and participation limitations. We used these data to develop a profile of our population of interest: adult Canadians with activity and participation limitations. Associations between demographic variables and self-reported causes of activity and participation limitations were assessed using multiple logistic regression. Results: One quarter of participants did not attribute their disability to any medical cause. The most prevalent medical conditions to which disabilities were attributed were musculoskeletal (46.1%), cardio/cerebrovascular (12.3%), mental health (8.4%), neurologic (6.0%), endocrine (6.0%) and respiratory (4.5%) conditions. Significant associations were noted between sociodemographic variables and participants’ attributions of medical conditions as cause of disability. Multiple logistic regression with bootstrapping showed that people who reported a medical cause for their limitation were more likely (p < 0.05) to be female, widowed, 40 years of age or older, born in Canada or white and were less likely (p < 0.05) to be in the highest income category or to be employed (i.e., to work more than 0 h/w). Interpretation: Most people living with activity and participation limitations report having a musculoskeletal disorder. However, a significant proportion of respondants did not attribute their limitations to a medical cause. PMID:21825051

  14. Possible changes for mudflow and avalanche activity in former Soviet Union due to the global warming

    SciTech Connect

    Glazovskaya, T.G.; Sidorova, T.L.; Seliverstov, Y.G.

    1996-12-31

    Past research, as well as laboratory evidence have revealed a relationship between climate, mudflow, and avalanche activity. It is possible to predict changes in mudflow and avalanche activity by using climate models. In this study, the GFDL model was used which contained data on mean monthly air temperature, precipitation, and carbon dioxide concentrations.

  15. Rate limiting activity of charge transfer during lithiation from ionic liquids

    NASA Astrophysics Data System (ADS)

    Rodrigues, Marco-Tulio F.; Lin, Xinrong; Gullapalli, Hemtej; Grinstaff, Mark W.; Ajayan, Pulickel M.

    2016-10-01

    Given the increased use of room temperature ionic liquid electrolytes in Li-ion batteries, due to their non-flammability and negligible volatility, this study evaluates the lithiation kinetics to understand and improve the rate performance of Li-ion batteries. Lithium titanate spinel is used as a model electrode and the electrolyte is composed of LiTFSI and TFSI-coordinated alkoxy-modified phosphonium ionic liquid. Based on the analysis of activation energies for each process, we report that the charge-transfer reaction at the electrode/electrolyte interface is the rate-limiting step for cell operation. This finding is further supported by the observation that a 50-fold decrease in charge-transfer resistance at higher temperatures leads to a significant performance improvement over that of a traditional organic electrolyte at room temperature. Charge-transfer resistance and electrolyte wetting on the electrode surface are critical processes for optimal battery performance, and such processes need to be included when designing new ionic liquids in order to exceed the power density obtained with the use of current carbonate-based electrolytes.

  16. Enhanced Xylitol Production by Mutant Kluyveromyces marxianus 36907-FMEL1 Due to Improved Xylose Reductase Activity.

    PubMed

    Kim, Jin-Seong; Park, Jae-Bum; Jang, Seung-Won; Ha, Suk-Jin

    2015-08-01

    A directed evolution and random mutagenesis were carried out with thermotolerant yeast Kluyveromyces marxianus ATCC 36907 for efficient xylitol production. The final selected strain, K. marxianus 36907-FMEL1, exhibited 120 and 39 % improvements of xylitol concentration and xylitol yield, respectively, as compared to the parental strain, K. marxianus ATCC 36907. According to enzymatic assays for xylose reductase (XR) activities, XR activity from K. marxianus 36907-FMEL1 was around twofold higher than that from the parental strain. Interestingly, the ratios of NADH-linked and NADPH-linked XR activities were highly changed from 1.92 to 1.30 when K. marxianus ATCC 36907 and K. marxianus 36907-FMEL1 were compared. As results of KmXYL1 genes sequencing, it was found that cysteine was substituted to tyrosine at position 36 after strain development which might cause enhanced XR activity from K. marxianus 36907-FMEL1.

  17. Coexistence of one- and two-dimensional supramolecular assemblies of terephthalic acid on Pd(111) due to self-limiting deprotonation

    NASA Astrophysics Data System (ADS)

    Cañas-Ventura, M. E.; Klappenberger, F.; Clair, S.; Pons, S.; Kern, K.; Brune, H.; Strunskus, T.; Wöll, Ch.; Fasel, R.; Barth, J. V.

    2006-11-01

    The adsorption of terephthalic acid [C6H4(COOH)2, TPA] on a Pd(111) surface has been investigated by means of scanning tunneling microscopy (STM), x-ray photoelectron spectroscopy, and near-edge x-ray absorption fine structure spectroscopy under ultrahigh vacuum conditions at room temperature. We find the coexistence of one- (1D) and two-dimensional (2D) molecular ordering. Our analysis indicates that the 1D phase consists of intact TPA chains stabilized by a dimerization of the self-complementary carboxyl groups, whereas in the 2D phase, consisting of deprotonated entities, the molecules form lateral ionic hydrogen bonds. The supramolecular growth dynamics and the resulting structures are explained by a self-limiting deprotonation process mediated by the catalytic activity of the Pd surface. Our models for the molecular ordering are supported by molecular mechanics calculations and a simulation of high resolution STM images.

  18. Limitations of facial immersion as a test of parasympathetic activity in man.

    PubMed Central

    Gallo, L; Maciel, B C; Manço, J C; Marin Neto, J A

    1988-01-01

    1. The heart rate response to immersion of the face in water, as an isolated manoeuvre or in combination with apnoea, was studied in eight normal volunteers to establish the conditions under which it could be used as a standardized, simple, non-invasive and reproducible test of parasympathetic activity. 2. The following procedures were evaluated: (a) 10 s apnoea in air at different lung volumes; (b) facial immersion in water for 2 min at various temperatures (5, 15 and 25 degrees C), with respiration maintained through a closed circuit; (c) combination of immersion and apnoea at different lung volumes. Three volunteers were re-evaluated after pharmacological blockade with atropine sulphate (0.04 mg/kg body weight). 3. The results showed that: (a) apnoea in air triggered lung volume-dependent heart rate responses; (b) facial immersion in water induced transient bradycardia which was maximum between 20 and 30 s of immersion; (c) there was no appreciable difference in the bradycardia evoked by immersion at different temperatures; (d) the combination of immersion and apnoea caused heterogeneous heart rate responses with no potentiation of bradycardia in relation to each manoeuvre as performed separately; (e) atropine did not reduce the magnitude of bradycardia induced by immersion in two of the subjects studied. 4. The variability of responses observed in the present study was probably due to the multiple receptors and afferent pathways that are simultaneously excited during these manoeuvres. As a consequence, the autonomic efferent response will depend on the unpredictable net effect of interaction of these mechanisms. This is a limiting factor for the standardization of this test as a simple and reproducible method for the assessment of parasympathetic activity. 5. Furthermore, the results obtained under pharmacological blockade indicate that the vagal efferent mechanism is not the only factor responsible for the bradycardia caused by facial immersion without apnoea

  19. The spatial structure of underwater noise due to shipping activities in the Celtic Sea

    NASA Astrophysics Data System (ADS)

    Chen, Feng; Shapiro, Georgy; Thain, Richard

    2014-05-01

    Underwater noise is now classed as pollution alongside chemical pollution and marine litter (MSFD, 2012). Underwater noise from man-made sources arises from a number of sources including shipping activities. There are numerous examples of sound-induced effects recorded for various marine mammals, either in controlled situations, or opportunistically (MSFD-GES, 2012). Broad or narrow band continuous sounds, as well as pulses, have been documented to cause effects ranging from slight behaviour change, to activity disruption, avoidance or abandonment of preferred habitat (see Clark et al., 2009). Underwater ambient noise generated by shipping activities has increased significantly over the past decades (e.g. Mcdonald et al., 2006). Noise from shipping is a major contributor to the ambient noise levels in ocean, particularly at low (

  20. Obesity in children and adolescents with chronic pain: Associations with pain and activity limitations

    PubMed Central

    Wilson, Anna C.; Samuelson, Bethany; Palermo, Tonya M.

    2010-01-01

    Objectives Obesity is associated with functional disability in adults with chronic pain, but less is known about obesity among youth with chronic pain. The purpose of this study was to 1) identify the prevalence of overweight and obesity in children and adolescents receiving treatment for chronic pain, and 2) examine associations between Body Mass Index (BMI), pain intensity, and activity limitations in this population. Methods Data was obtained from records of 118 patients, ages 8 to 18, seen in a multidisciplinary pediatric pain clinic. Information about age, gender, pain problem, duration and severity, medical diagnoses, medications, height and weight were collected from medical records and intake questionnaires. The CDC’s pediatric BMI calculator was used to obtain percentile and category (underweight, healthy weight, overweight, obese). Children and parents completed the Child Activity Limitations Interview-21 (CALI-21), a self-report measure of activity limitations. Results A significantly higher rate of overweight and obesity was observed among youth with chronic pain compared to a normative sample. BMI percentile was predictive of concurrent limitations in vigorous activities, according to parent report. Discussion BMI percentile and weight status may contribute to activity limitations among children and adolescents with chronic pain. Weight status is an important factor to consider in the context of treatment of chronic pain and disability in children and adolescents. PMID:20664337

  1. Changes in antibacterial activity of triclosan and sulfa drugs due to photochemical transformations.

    PubMed

    Wammer, Kristine H; Lapara, Timothy M; McNeill, Kristopher; Arnold, William A; Swackhamer, Deborah L

    2006-06-01

    Sulfa drugs and triclosan represent two classes of antibacterials that have been found in natural waters and for which photodegradation is anticipated to be a significant loss process. Parent antibacterial compounds and the products of photolysis reactions were compared for three sulfa drugs and triclosan to determine the extent to which photolysis affects their antibacterial potency on Escherichia coli DH5alpha. Sulfathiazole (median effective concentration [EC50] = 20.0 microM), sulfamethoxazole (EC50 = 12.3 microM), and sulfachloropyridazine (EC50 = 6.9 microM) inhibited bacterial growth but did not affect respiratory activity. Photolysis products of these sulfa drugs did not retain any measurable ability to inhibit growth. Triclosan inhibited both the growth (EC50 = 0.24 microM) and respiratory activity of E. coli DH5alpha. Triclosan photolysis products also exhibited no measurable effect on growth or respiratory activity. These experiments indicate that the products of triclosan and sulfa drug photolysis are unlikely to possess antibacterial activity in natural waters. The rapid screening method used for these two classes of compounds will be useful for helping to identify photolabile antibacterial compounds, for which photoproducts could require further investigation.

  2. 131I activity in urine to the sewer system due to thyroidal treatments.

    PubMed

    Andrés, C; Barquero, R; Tortosa, R; Nuñez, C; del Castillo, A; Vega-Carrillo, H R; Alonso, D

    2011-08-01

    In nuclear medicine, estimating the radioactivity contained in the urine of patients treated with I and discharged to the environment could prevent the exposure of a population to radioactive effluents and the pollution of the aquatic environment with ionizing radiation. This can be a regulatory requirement (as in Spain) or requested by the sewer authority. Seventy-nine differentiated thyroid cancer cases (undergone as inpatients) and 187 hyperthyroidism cases (undergone as outpatients) were treated in our hospital with I throughout the year 2009. In hyperthyroidism treatments, the effective elimination constant was used to calculate the corresponding discharged activity in the urine, giving an activity level always below 0.7 GBq. In differentiated thyroid cancer treatments, patient's urine was collected in storage tanks during the hospitalization. Measurements of external exposure at 1 m made every day were used to calculate the activity contained in the urine. The tank activity was always below 15 GBq, but always higher than 2 GBq. Obtained results show that effective doses to sewage workers, received from liquid discharges, can only be reduced to less than 10 μSv if storage tanks are installed. Without tanks, 157 μSv can be reached, above the constrain dose used in nuclear installations (100 μSv). Our calculations may be helpful to the regulatory authority to review the clinical radiation waste normative, especially in countries where the discharges are released directly into public sewage plants. PMID:21709491

  3. Modeling of geomagnetic activity due to passage of different structures and features of high speed streams

    NASA Astrophysics Data System (ADS)

    Mustajab, Fainana

    2016-07-01

    The modeling of terrestrial environment and relative geoeffectiveness due to high speed streams of different type and also compare their geoeffectiveness due to fine structures associated with streams, for example i) streams with different speed, ii) streams with different durations, iii) streams from different solar source and iv) associated fine structures. We also observed high speed streams during 1996 to 2011, and divided them into convenient groups based on their i) speed, ii) durations, iii) solar sources and iv) Dst groups. Performed them method of superposed-epoch analysis and other some statistical-analysis and correlation analysis between geomagnetic index Dst and plasma/field parameters during for both main phase and recovery phase. Streams having the passage duration ranging from 4.5 days to 10.5 days is 59% while other groups, having passage duration <4.5 days and > 10.5 days, contribute only near about 13%. When we observe group according to speed of streams, 30% of high speed streams are having the speed >650km/s and other groups are near about equally distributed in the range 400km/s to 650km/s. Out of 575 high speed streams, 45% streams are caused by single coronal hole, 20% due to multiple coronal hole, 24% by compound i.e: due to coronal hole and coronal mass ejections and only 10% from coronal mass ejections. The streams which are responsible for quiet, weak, moderate storms are nearly equal and only 12% streams cause severe storms. Dst gives best correlation with V(km/s) and BVres to the power 2 (x10res to the power 6) for over all storm time. B(nT) and BV(x10res to the power 3) represent good correlation with Dst during recovery phase duration for the speed groups. I observed the percentage of quiet storms decreases with increasing speed of streams. Near about equal percentage of weak storm are observed in each set of speed of stream. 17% moderate storms are found to contribute for the speed range 400-550km/s and ≈33% contribution is

  4. Activity pattern and energy expenditure due to physical activity before and during pregnancy in healthy Swedish women.

    PubMed

    Lof, Marie; Forsum, Elisabet

    2006-02-01

    Human pregnancy is associated with increased requirements for dietary energy and this increase may be partly offset by reductions in physical activity during gestation. Studies in well-nourished women have shown that the physical activity level (PAL), obtained as the total energy expenditure (TEE) divided by the BMR, decreases in late pregnancy. However, it is not known if this decrease is really caused by reductions in physical activity or if it is the result of decreases in energy expenditure/BMR (the so-called metabolic equivalent, MET) for many activities in late pregnancy. In the present study activity pattern, TEE and BMR were assessed in twenty-three healthy Swedish women before pregnancy as well as in gestational weeks 14 and 32. Activity pattern was assessed using a questionnaire and heart rate recording. TEE was assessed using the doubly labelled water method and BMR was measured by means of indirect calorimetry. When compared to the pre-pregnant value, there was little change in the PAL in gestational week 14 but it was significantly reduced in gestational week 32. Results obtained by means of the questionnaire and by heart rate recording showed that the activity pattern was largely unaffected by pregnancy. The findings support the following conclusion: in a population of well-nourished women where the activity pattern is maintained during pregnancy, the increase in BMR represents approximately the main part of the pregnancy-induced increase in TEE, at least until gestational week 32.

  5. Low limit of Mn 2+-activated cathodoluminescence of calcite: state of the art

    NASA Astrophysics Data System (ADS)

    Habermann, Dirk; Neuser, Rolf D.; Richter, Detlev K.

    1998-02-01

    In the literature, the lower limit for Mn 2+-activated cathodoluminescence (CL) of calcite is variously reputed to over a very wide range of values above 10 ppm Mn. Our spectroscopic investigations of the CL response in natural calcite reveal that below 10 ppm manganese content Mn 2+-activation is also present. Using the Quantitative High Resolution Spectral analysis of CL (QHRS-CL) an activation by Mn 2+ in the range of 700 ppb is proved, which cannot be determined visually. So, if not quenched, the minimum Mn 2+ content for Mn 2+-activation is one atom in the irradiated calcite crystal lattice volume. As the intrinsic (background blue) luminescence is used to determine non-altered biogenic calcite, the limit of Mn 2+-activation plays an important role in the interpretation of diagenetic processes. Our results of spectroscopic analyses require a revision of current opinions about the diagenesis of calcite as revealed by CL investigation.

  6. Excitation of skeletal muscle is a self-limiting process, due to run-down of Na+, K+ gradients, recoverable by stimulation of the Na+, K+ pumps

    PubMed Central

    Clausen, Torben

    2015-01-01

    The general working hypothesis of this study was that muscle fatigue and force recovery depend on passive and active fluxes of Na+ and K+. This is tested by examining the time-course of excitation-induced fluxes of Na+ and K+ during 5–300 sec of 10–60 Hz continuous electrical stimulation in rat extensor digitorum longus (EDL) muscles in vitro and in vivo using 22Na and flame photometric determination of Na+ and K+. 60 sec of 60 Hz stimulation rapidly increases 22Na influx, during the initial phase (0–15 sec) by 0.53 μmol(sec)−1(g wet wt.)−1, sixfold faster than in the later phase (15–60 sec). These values agree with flame photometric measurements of Na+ content. The progressive reduction in the rate of excitation-induced Na+ uptake is likely to reflect gradual loss of excitability due to accumulation of K+ in the extracellular space and t-tubules leading to depolarization. This is in keeping with the concomitant progressive loss of contractile force previously demonstrated. During electrical stimulation rat muscles rapidly reach high rates of active Na+, K+-transport (in EDL muscles a sevenfold increase and in soleus muscles a 22-fold increase), allowing efficient and selective compensation for the large excitation-induced passive Na+, K+-fluxes demonstrated over the latest decades. The excitation-induced changes in passive fluxes of Na+ and K+ are both clearly larger than previously observed. The excitation-induced reduction in [Na+]o contributes considerably to the inhibitory effect of elevated [K+]o. In conclusion, excitation-induced passive and active Na+ and K+ fluxes are important causes of muscle fatigue and force recovery, respectively. PMID:25862098

  7. Mental Health in Multiple Sclerosis Patients without Limitation of Physical Function: The Role of Physical Activity.

    PubMed

    Tallner, Alexander; Waschbisch, Anne; Hentschke, Christian; Pfeifer, Klaus; Mäurer, Mathias

    2015-07-02

    Multiple sclerosis (MS) patients, in general, show reduced physical function, physical activity, and quality of life. Positive associations between physical activity and quality of life have been reported. In particular, we were interested in the relation between physical activity and mental health in MS patients without limitation of physical function, since limitations of physical function may influence both physical activity and quality of life. Assessment comprised the Baecke questionnaire on physical activity, the Short Form 36 Health Survey (SF-36), and Beck Depression Inventory (BDI). We ranked our sample according to physical activity into four groups and performed an ANOVA to analyze the relationship between levels of physical activity and health-related quality of life (HRQoL). Then we performed a subgroup analysis and included patients with unlimited walking distance and a score of less than 18 in the BDI. Most active vs. inactive patients were compared for the mental subscales of the SF-36 and depression scores. From 632 patients, 265 met inclusion criteria and hence quartiles were filled with 67 patients each. Active and inactive patients did not differ considerably in physical function. In contrast, mental subscales of the SF-36 were higher in active patients. Remarkable and significant differences were found regarding vitality, general health perception, social functioning and mental health, all in favor of physically active patients. Our study showed that higher physical activity is still associated with higher mental health scores even if limitations of physical function are accounted for. Therefore, we believe that physical activity and exercise have considerable health benefits for MS patients.

  8. Priming the Holiday Spirit: Persistent Activation due to Extra-Experimental Experiences

    PubMed Central

    Coane, Jennifer H.; Balota, David A.

    2010-01-01

    The concept of activation is a critical component of many models of cognition. A key characteristic of activation is that recent experience with a concept or stimulus increases the accessibility of the corresponding representation. The extent to which increases in accessibility occur as a result of experiences outside of laboratory settings has not been extensively explored. In the present study, we presented lexical stimuli associated to different holidays and festivities over the course of a year in a lexical decision task. When stimulus meaning and time of testing were congruent (e.g., leprechaun in March), response times were faster and accuracy greater than when meaning and time of test were incongruent (e.g., leprechaun in November). Congruency also benefited performance on a surprise free recall task of the items presented earlier in the lexical decision task. Discussion focuses on potential theoretical accounts of this heightened accessibility of time-of-the-year relevant concepts. PMID:19966266

  9. Massive stars: flare activity due to infalls of comet-like bodies

    NASA Astrophysics Data System (ADS)

    Ibadov, Subhon; Ibodov, Firuz S.

    2015-01-01

    Passages of comet-like bodies through the atmosphere/chromosphere of massive stars at velocities more than 600 km/s will be accompanied, due to aerodynamic effects as crushing and flattening, by impulse generation of hot plasma within a relatively very thin layer near the stellar surface/photosphere as well as ``blast'' shock wave, i.e., impact-generated photospheric stellar/solar flares. Observational manifestations of such high-temperature phenomena will be eruption of the explosive layer's hot plasma, on materials of the star and ``exploding'' comet nuclei, into the circumstellar environment and variable anomalies in chemical abundances of metal atoms/ions like Fe, Si etc. Interferometric and spectroscopic observations/monitoring of young massive stars with dense protoplanetary discs are of interest for massive stars physics/evolution, including identification of mechanisms for massive stars variability.

  10. Activity of cathepsins in rat's spleen due to experimentally induced pancreatitis.

    PubMed

    Maciejewski, R; Burdan, F; Madej, B; Kiś, G; Szkodziak, P; Burski, K

    The aim of this study was to establish and quantify the changes of the level of cathepsin B, D and L in the spleen during experimental pancreatitis. The experiment was carried out in 115 male Wistar rats, randomly divided into three groups: intact (n = 15), injected with 0.9% NaCl solution into the common bile pancreatic duct (n = 50) and injected with 5% sodium taurocholate into this duct to induce acute pancreatitis (n = 50). After 2, 6, 12, 24 and 48 hours rats were anaesthetised, and blood was taken for amylase determination from the heart, and the spleen was removed. Alpha-amylase level in the blood serum samples was measured by enzymatic method. Cathepsin activity was established by spectrophotometric methods using substrates which form coloured complexes when they react with these proteases. The specific free fraction activity of cathepsin B, D and L in the spleen changed during the course of experiment, but there was no correlation between their activity and the intensity of pancreatitis established by serum amylase level.

  11. The Antimicrobial Activity of Marinocine, Synthesized by Marinomonas mediterranea, Is Due to Hydrogen Peroxide Generated by Its Lysine Oxidase Activity

    PubMed Central

    Lucas-Elío, Patricia; Gómez, Daniel; Solano, Francisco; Sanchez-Amat, Antonio

    2006-01-01

    Marinocine is a broad-spectrum antibacterial protein synthesized by the melanogenic marine bacterium Marinomonas mediterranea. This work describes the basis for the antibacterial activity of marinocine and the identification of the gene coding for this protein. The antibacterial activity is inhibited under anaerobic conditions and by the presence of catalase under aerobic conditions. Marinocine is active only in culture media containing l-lysine. In the presence of this amino acid, marinocine generates hydrogen peroxide, which causes cell death as confirmed by the increased sensitivity to marinocine of Escherichia coli strains mutated in catalase activity. The gene coding for this novel enzyme was cloned using degenerate PCR with primers designed based on conserved regions in the antimicrobial protein AlpP, synthesized by Pseudoalteromonas tunicata, and some hypothetical proteins. The gene coding for marinocine has been named lodA, standing for lysine oxidase, and it seems to form part of an operon with a second gene, lodB, that codes for a putative dehydrogenase flavoprotein. The identity of marinocine as LodA has been demonstrated by N-terminal sequencing of purified marinocine and generation of lodA mutants that lose their antimicrobial activity. This is the first report on a bacterial lysine oxidase activity and the first time that a gene encoding this activity has been cloned. PMID:16547036

  12. Coma Morphology Due to an Extended Active Region and Implications for the Spin State of Comet Hale-Bopp

    NASA Technical Reports Server (NTRS)

    Samarasinha, Nalin H.

    2000-01-01

    We show that the circular character of continuum structures observed in the coma of comet Hale-Bopp around the perihelion passage is most likely due to a dust jet from a large extended active region on the surface. Coma morphology due to a wide jet is different from that due to a narrow jet. The latter shows foreshortening effects due to observing geometry, wider jet produces more circular features. This circularization effect provides a self-consistent explanation for the evolution of near-perihelion coma morphology. No changes in the direction of the rotational angular momentum vector are required during this period in contrast to the models of Schleicher et al. This circularization effect also enables us to produce near-circular coma features in the S-E quadrant during 1997 late February and therefore questions the basic premise on which Sekanina bases his morphological arguments for a gravitationally bound satellite nucleus.

  13. Estimation of landslides activities evolution due to land-use changes in a Pyrenean valley

    NASA Astrophysics Data System (ADS)

    Vandromme, Rosalie; Desramaut, Nicolas; Cottin, Léa; Bernardie, Séverine; Grandjean, Gilles

    2015-04-01

    Global changes would have impacts worldwide, but their effects should be even more exacerbated in areas particularly vulnerable. Mountainous areas are among these vulnerable territories. Ecological systems are often at a fragile equilibrium, socio-economical activities are often climate-dependent and climate-driven natural hazards can be a major threat for human activities. In order to estimate the capacity of such mountainous valleys to face global changes (climate, but also climate- and human- induced land-use changes), it is necessary to be able to evaluate the evolution of the different threats. The present work presents a method to evaluate the influences of the evolution of both climate and vegetation cover on landslides activities over a whole valley, to propose adequate solutions for current and future forestry management. It is therefore necessary to properly estimate the vegetation influences on slope stabilities. In the present study, we develop a complementary module to our large-scale slope stability assessment tool to take into account the effects of vegetation on the mechanical soil properties (cohesion and over-load), but also on the slope hydrology (change in interceptions, run-off, and infiltration). Hence the proposed method combines a mechanical stability model (using finite slope analysis), a hydrological model, and a vegetation module which interfere with both aspects. All these elements are interfaced within a GIS-based solution. The whole chain is applied to a 100-km² Pyrenean Valley, for the ANR Project SAMCO (Society Adaptation for coping with Mountain risks in a global change COntext), as a first step in the chain for risk assessment for different climate and economical development scenarios, to evaluate the resilience of mountainous areas.

  14. The Very High Premature Mortality Rate among Active Professional Wrestlers Is Primarily Due to Cardiovascular Disease

    PubMed Central

    Herman, Christopher W.; Conlon, Anna S. C.; Rubenfire, Melvyn; Burghardt, Andrew R.; McGregor, Stephen J.

    2014-01-01

    Purpose Recently, much media attention has been given to the premature deaths in professional wrestlers. Since no formal studies exist that have statistically examined the probability of premature mortality in professional wrestlers, we determined survival estimates for active wresters over the past quarter century to establish the factors contributing to the premature mortality of these individuals. Methods Data including cause of death was obtained from public records and wrestling publications in wrestlers who were active between January 1, 1985 and December 31, 2011. 557 males were considered consistently active wrestlers during this time period. 2007 published mortality rates from the Center for Disease Control were used to compare the general population to the wrestlers by age, BMI, time period, and cause of death. Survival estimates and Cox hazard regression models were fit to determine incident premature deaths and factors associated with lower survival. Cumulative incidence function (CIF) estimates given years wrestled was obtained using a competing risks model for cause of death. Results The mortality for all wrestlers over the 26-year study period was.007 deaths/total person-years or 708 per 100,000 per year, and 16% of deaths occurred below age 50 years. Among wrestlers, the leading cause of deaths based on CIF was cardiovascular-related (38%). For cardiovascular-related deaths, drug overdose-related deaths and cancer deaths, wrestler mortality rates were respectively 15.1, 122.7 and 6.4 times greater than those of males in the general population. Survival estimates from hazard models indicated that BMI is significantly associated with the hazard of death from total time wrestling (p<0.0001). Conclusion Professional wrestlers are more likely to die prematurely from cardiovascular disease compared to the general population and morbidly obese wrestlers are especially at risk. Results from this study may be useful for professional wrestlers, as well as

  15. Coal mining activities change plant community structure due to air pollution and soil degradation.

    PubMed

    Pandey, Bhanu; Agrawal, Madhoolika; Singh, Siddharth

    2014-10-01

    The aim of this study was to investigate the effects of coal mining activities on the community structures of woody and herbaceous plants. The response of individual plants of community to defilement caused by coal mining was also assessed. Air monitoring, soil physico-chemical and phytosociological analyses were carried around Jharia coalfield (JCF) and Raniganj coalfield. The importance value index of sensitive species minified and those of tolerant species enhanced with increasing pollution load and altered soil quality around coal mining areas. Although the species richness of woody and herbaceous plants decreased with higher pollution load, a large number of species acclimatized to the stress caused by the coal mining activities. Woody plant community at JCF was more affected by coal mining than herbaceous community. Canonical correspondence analysis revealed that structure of herbaceous community was mainly driven by soil total organic carbon, soil nitrogen, whereas woody layer community was influenced by sulphur dioxide in ambient air, soil sulphate and soil phosphorus. The changes in species diversity observed at mining areas indicated an increase in the proportion of resistant herbs and grasses showing a tendency towards a definite selection strategy of ecosystem in response to air pollution and altered soil characteristics.

  16. Telmisartan prevented cognitive decline partly due to PPAR-{gamma} activation

    SciTech Connect

    Mogi, Masaki; Li Jianmei; Tsukuda, Kana; Iwanami, Jun; Min, Li-Juan; Sakata, Akiko; Fujita, Teppei; Iwai, Masaru; Horiuchi, Masatsugu

    2008-10-24

    Telmisartan is a unique angiotensin receptor blocker (ARB) and partial agonist of peroxisome proliferator-activated receptor (PPAR)-{gamma}. Here, we investigated the preventive effect of telmisartan on cognitive decline in Alzheimer disease. In ddY mice, intracerebroventricular injection of A{beta} 1-40 significantly attenuated their cognitive function evaluated by shuttle avoidance test. Pretreatment with a non-hypotensive dose of telmisartan significantly inhibited such cognitive decline. Interestingly, co-treatment with GW9662, a PPAR-{gamma} antagonist, partially inhibited this improvement of cognitive decline. Another ARB, losartan, which has less PPAR-{gamma} agonistic effect, also inhibited A{beta}-injection-induced cognitive decline; however the effect was smaller than that of telmisartan and was not affected by GW9662. Immunohistochemical staining for A{beta} showed the reduced A{beta} deposition in telmisartan-treated mice. However, this reduction was not observed in mice co-administered GW9662. These findings suggest that ARB has a preventive effect on cognitive impairment in Alzheimer disease, and telmisartan, with PPAR-{gamma} activation, could exert a stronger effect.

  17. Are the changes in the peripheral brain-derived neurotrophic factor levels due to platelet activation?

    PubMed Central

    Serra-Millàs, Montserrat

    2016-01-01

    Brain-derived neurotrophic factor (BDNF) plays an important role in central nervous system development, neurogenesis and neuronal plasticity. BDNF is also expressed in several non-neuronal tissues, and it could play an important role in other processes, such as cancer, angiogenesis, etc. Platelets are the major source of peripheral BDNF. However, platelets also contain high amounts of serotonin; they express specific surface receptors during activation, and a multitude of pro-inflammatory and immunomodulatory bioactive compounds are secreted from the granules. Until recently, there was insufficient knowledge regarding the relationship between BDNF and platelets. Recent studies showed that BDNF is present in two distinct pools in platelets, in α-granules and in the cytoplasm, and only the BDNF in the granules is secreted following stimulation, representing 30% of the total BDNF in platelets. BDNF has an important role in the pathophysiology of depression. Low levels of serum BDNF have been described in patients with major depressive disorder, and BDNF levels increased with chronic antidepressant treatment. Interestingly, there is an association between depression and platelet function. This review analyzed studies that evaluated the relationship between BDNF and platelet activation and the effect of treatments on both parameters. Only a few studies consider this possible confounding factor, and it could be very important in diseases such as depression, which show changes in both parameters. PMID:27014600

  18. Platelet Activation Due to Hemodynamic Shear Stresses: Damage Accumulation Model and Comparison to In Vitro Measurements

    PubMed Central

    Nobili, Matteo; Sheriff, Jawaad; Morbiducci, Umberto; Redaelli, Alberto; Bluestein, Danny

    2009-01-01

    The need to optimize the thrombogenic performance of blood recirculating cardiovascular devices, e.g., prosthetic heart valves (PHV) and ventricular assist devices (VAD), is accentuated by the fact that most of them require lifelong anticoagulation therapy that does not eliminate the risk of thromboembolic complications. The formation of thromboemboli in the flow field of these devices is potentiated by contact with foreign surfaces and regional flow phenomena that stimulate blood clotting, especially platelets. With the lack of appropriate methodology, device manufacturers do not specifically optimize for thrombogenic performance. Such optimization can be facilitated by formulating a robust numerical methodology with predictive capabilities of flow-induced platelet activation. In this study, a phenomenological model for platelet cumulative damage, identified by means of genetic algorithms (GAs), was correlated with in vitro experiments conducted in a Hemodynamic Shearing Device (HSD). Platelets were uniformly exposed to flow shear representing the lower end of the stress levels encountered in devices, and platelet activity state (PAS) was measured in response to six dynamic shear stress waveforms representing repeated passages through a device, and correlated to the predictions of the damage accumulation model. Experimental results demonstrated an increase in PAS with a decrease in “relaxation” time between pulses. The model predictions were in very good agreement with the experimental results. PMID:18204318

  19. Efficient influenza B virus propagation due to deficient interferon-induced antiviral activity in MDCK cells.

    PubMed

    Frensing, Timo; Seitz, Claudius; Heynisch, Bjoern; Patzina, Corinna; Kochs, Georg; Reichl, Udo

    2011-09-22

    Influenza B virus infections are mainly restricted to humans, which is partially caused by the inability of influenza B virus NS1 protein to counteract the innate immune response of other species. However, for cell culture-based influenza vaccine production non-human cells, such as Madin-Darby canine kidney (MDCK) cells, are commonly used. Therefore, the impact of cellular pathogen defence mechanisms on influenza B virus propagation in MDCK cells was analysed in this study. Activation of the cellular antiviral defence by interferon stimulation slowed down influenza B virus replication at early time points but after 48h the same virus titres were reached in stimulated and control cells. Furthermore, suppression of the antiviral host defence by transient expression of a viral antagonist, the rabies virus phosphoprotein, could not increase influenza B virus replication. Finally, canine Myxovirus resistance (Mx) proteins showed no antiviral activity in an influenza B virus-specific minireplicon assay in contrast to the murine Mx1 protein. Taken together, these results indicate that an insufficient antiviral defence in MDCK cells promotes efficient influenza B virus replication favouring the use of MDCK cells in influenza vaccine production.

  20. Biological Activities of Uric Acid in Infection Due to Enteropathogenic and Shiga-Toxigenic Escherichia coli

    PubMed Central

    Broome, Jacqueline E.; Lis, Agnieszka

    2016-01-01

    In previous work, we identified xanthine oxidase (XO) as an important enzyme in the interaction between the host and enteropathogenic Escherichia coli (EPEC) and Shiga-toxigenic E. coli (STEC). Many of the biological effects of XO were due to the hydrogen peroxide produced by the enzyme. We wondered, however, if uric acid generated by XO also had biological effects in the gastrointestinal tract. Uric acid triggered inflammatory responses in the gut, including increased submucosal edema and release of extracellular DNA from host cells. While uric acid alone was unable to trigger a chloride secretory response in intestinal monolayers, it did potentiate the secretory response to cyclic AMP agonists. Uric acid crystals were formed in vivo in the lumen of the gut in response to EPEC and STEC infections. While trying to visualize uric acid crystals formed during EPEC and STEC infections, we noticed that uric acid crystals became enmeshed in the neutrophilic extracellular traps (NETs) produced from host cells in response to bacteria in cultured cell systems and in the intestine in vivo. Uric acid levels in the gut lumen increased in response to exogenous DNA, and these increases were enhanced by the actions of DNase I. Interestingly, addition of DNase I reduced the numbers of EPEC bacteria recovered after a 20-h infection and protected against EPEC-induced histologic damage. PMID:26787720

  1. Possible sea sediments due to glaciofluvial activity in Elysium Planitia, Mars

    NASA Astrophysics Data System (ADS)

    Nussbaumer, J.

    Observations of fluvial morphologies in southern Elysium Planitia strongly supports the hypothesis that water substantially affected this region during the relatively recent geologic past. As of yet, however, the extent of a standing body of water has been speculative. The observation of zig-zag features potentially analogous to those observed near the Wadden Sea on Earth [see 1] may help show in more detail the origin, activity, and fate of water in this region of Mars. These terrestrial analogs could constrain environmental scenarios concerning the formation of these features. We present a geomorphologic map of central Elysium Planitia, that aids in our interpretation of potentially site-specific depositional/erosional morphologies. Positive relief zig-zag features within the Medusae Fossae Formation (Themis Image V05875001) resemble similar structures on Earth observed at shorelines of flat regions. Glaciofluvial activity is indicated by linear features resembling straight glacial flutings, which could form aeolian yardangs subsequently. The flutings are associated with branches of inverted fluvial channels (Images Themis V05588002, MOC e1800307). Their excavated positive relief (height ~40 m) indicates, that the adjacent material was eroded by sublimation or aeolian activity. The channels possibly resemble ice marginal channels. A high resolution Digital Terrain Model of one of the channels suggests, that one channel is possibly running upslope. Fluvial processes could have operated at one location at one time, and glacial processes at another location at another time [2]. A glacial drainage system [see 3] is a possible terrestrial analog for one inverted fluvial channel on Mars (Themis Image V05875001). Flutings occur on the foreland of many glaciers and their length may provide important evidence for rapid advance over substantial distances. Flutings are the product of subglacial erosion and transport processes [4]. By assigning the different environmental

  2. On Stellar Activity Enhancement Due to Interactions with Extrasolar Giant Planets.

    PubMed

    Cuntz; Saar; Musielak

    2000-04-20

    We present a first attempt to identify and quantify possible interactions between recently discovered extrasolar giant planets (and brown dwarfs) and their host stars, resulting in activity enhancement in the stellar outer atmospheres. Many extrasolar planets have masses comparable to or larger than Jupiter and are within a distance of 0.5 AU, suggesting the possibility of their significant influence on stellar winds, coronae, and even chromospheres. Beyond the well-known rotational synchronization, the interactions include tidal effects (in which enhanced flows and turbulence in the tidal bulge lead to increased magnetoacoustic heating and dynamo action) and direct magnetic interaction between the stellar and planetary magnetic fields. We discuss relevant parameters for selected systems and give preliminary estimates of the relative interaction strengths.

  3. CYCLIC MAGNETIC ACTIVITY DUE TO TURBULENT CONVECTION IN SPHERICAL WEDGE GEOMETRY

    SciTech Connect

    Kaepylae, Petri J.; Mantere, Maarit J.; Brandenburg, Axel

    2012-08-10

    We report on simulations of turbulent, rotating, stratified, magnetohydrodynamic convection in spherical wedge geometry. An initially small-scale, random, weak-amplitude magnetic field is amplified by several orders of magnitude in the course of the simulation to form oscillatory large-scale fields in the saturated state of the dynamo. The differential rotation is solar-like (fast equator), but neither coherent meridional poleward circulation nor near-surface shear layer develop in these runs. In addition to a poleward branch of magnetic activity beyond 50 Degree-Sign latitude, we find for the first time a pronounced equatorward branch at around 20 Degree-Sign latitude, reminiscent of the solar cycle.

  4. Mitigation of Autoignition Due to Premixing in a Hypervelocity Flow Using Active Wall Cooling

    NASA Technical Reports Server (NTRS)

    Axdahl, Erik; Kumar, Ajay; Wilhite, Alan

    2013-01-01

    Preinjection of fuel on the forebody of an airbreathing vehicle is a proposed method to gain access to hypervelocity flight Mach numbers. However, this creates the possibility of autoignition either near the wall or in the core of the flow, thereby consuming fuel prematurely as well as increasing the amount of pressure drag on the vehicle. The computational fluid dynamics code VULCAN was used to conduct three dimensional simulations of the reacting flow in the vicinity of hydrogen injectors on a flat plate at conditions relevant to a Mach 12 notional flight vehicle forebody to determine the location where autoignition occurs. Active wall cooling strategies were formulated and simulated in response to regions of autoignition. It was found that tangential film cooling using hydrogen or helium were both able to nearly or completely eliminate wall autoignition in the flow domain of interest.

  5. Monthly Variability in Upper Ocean Biogeochemistry Due to Mesoscale Eddy Activity in the Sargasso Sea

    NASA Technical Reports Server (NTRS)

    Sweeney, Erin N.

    2001-01-01

    A comparison of monthly biogeochemical measurements made from 1993 to 1995, combined with hydrography and satellite altimetry, was used to observe the impacts of nine eddy events on primary productivity and particle flux in the Sargasso Sea. Measurements of primary production, thorium-234 flux, nitrate+nitrite, and photosynthetic pigments made at the US JGOFS Bermuda Atlantic Time-Series Study (BATS) site were used. During the three years of this study, four out of six high thorium-234 flux events over 1000 dpm/sq m/d occurred during the passage of an eddy. Primary production nearly as high as the spring bloom maximum was observed in two mode-water eddies (May 1993 and July 1995). The 1994 spring bloom at BATS was suppressed by the passage of an anticyclone. Distinct phytoplankton community shifts were observed in mode-water eddies, which had an increased percentage diatoms and dinoflagelletes, and in cyclones, which had an increased percentage cyanobacteria (excluding Prochlorococcus). The difference in the observations of mode-water eddies and cyclones may result from the age of the eddy, which was very important to the biological response. In general, eddies that were one to two months old elicited a large biological response; eddies that were three months old may show a biological response and were accompanied by high thorium flux measurements; eddies that were four months old or older did not show a biological response or high thorium flux. Our conceptual model depicting the importance of temporal changes during eddy upwelling and decay fit the observations well in all seven upwelling eddies. Additional information is needed to determine the importance of deeper mixed layers and winter mixing to the magnitude of the eddy impacts. Also, sampling generally captured only the beginning, end, and/or edge of an eddy due to the monthly to semi-monthly frequency of the measurements made at BATS. Lagrangian studies, higher resolution time-series, and/or more spatial

  6. Monthly Variability in Upper Ocean Biogeochemistry due to Mesoscale Eddy Activity in the Sargasso Sea

    NASA Technical Reports Server (NTRS)

    Sweeney, Erin N.

    2001-01-01

    A comparison of monthly biogeochemical measurements made from 1993 to 1995, combined with hydrography and satellite altimetry, was used to observe the impacts of nine eddy events on primary productivity and particle flux in the Sargasso Sea. Measurements of primary production, thorium-234 flux, nitrate+nitrite, and photosynthetic pigments made at the US JGOFS Bermuda Atlantic Time-series Study (BATS) site were used. During the three years of this study, four out of six high thorium-234 flux events over 1000 dpm/sq m/d occurred during the passage of an eddy. Primary production nearly as high as the spring bloom maximum was observed in two modewater eddies (May 1993 and July 1995). The 1994 spring bloom at BATS was suppressed by the passage of an anticyclone. Distinct phytoplankton community shifts were observed in mode-water eddies, which had an increased percentage diatoms and dinoflagelletes, and in cyclones, which had an increased percentage cyanobacteria (excluding Prochlorococcus). The difference in the observations of mode-water eddies and cyclones may result from the age of the eddy, which was very important to the biological response. In general, eddies that were one to two months old elicited a large biological response; eddies that were three months old may show a biological response and were accompanied by high thorium flux measurements, eddies that were four months old or older did not show a biological response or high thorium flux. Our conceptual model depicting the importance of temporal changes during eddy upwelling and decay fit the observations well in all 7 upwelling eddies. Additional information is needed to determine the importance of deeper mixed layers and winter mixing to the magnitude of the eddy impacts. Also, sampling generally captured only the beginning, end, and /or edge of an eddy due to the monthly to semi-monthly frequency of the measurements made at BATS. Lagrangian studies, higher resolution time-series, and/or more spatial

  7. RADIAL VELOCITY OFFSETS DUE TO MASS OUTFLOWS AND EXTINCTION IN ACTIVE GALACTIC NUCLEI

    SciTech Connect

    Crenshaw, D. M.; Schmitt, H. R.; Kraemer, S. B.; Mushotzky, R. F.

    2010-01-01

    We present a study of the radial velocity offsets between narrow emission lines and host galaxy lines (stellar absorption and H I 21 cm emission) in Seyfert galaxies with observed redshifts less than 0.043. We find that 35% of the Seyferts in the sample show [O III] emission lines with blueshifts with respect to their host galaxies exceeding 50 km s{sup -1}, whereas only 6% show redshifts this large, in qualitative agreement with most previous studies. We also find that a greater percentage of Seyfert 1 galaxies show blueshifts than Seyfert 2 galaxies. Using Hubble Spce Talescope/Space Telescope Imaging Spectrograph spatially resolved spectra of the Seyfert 2 galaxy NGC 1068 and the Seyfert 1 galaxy NGC 4151, we generate geometric models of their narrow-line regions (NLRs) and inner galactic disks, and show how these models can explain the blueshifted [O III] emission lines in collapsed STIS spectra of these two Seyferts. We conclude that the combination of mass outflow of ionized gas in the NLR and extinction by dust in the inner disk (primarily in the form of dust spirals) is primarily responsible for the velocity offsets in Seyfert galaxies. More exotic explanations are not needed. We discuss the implications of this result for the velocity offsets found in higher redshift active galactic nuclei.

  8. Pulmonary arterial hypertension in rats due to age-related arginase activation in intermittent hypoxia.

    PubMed

    Nara, Akina; Nagai, Hisashi; Shintani-Ishida, Kaori; Ogura, Sayoko; Shimosawa, Tatsuo; Kuwahira, Ichiro; Shirai, Mikiyasu; Yoshida, Ken-ichi

    2015-08-01

    Pulmonary arterial hypertension (PAH) is prevalent in patients with obstructive sleep apnea syndrome (OSAS). Aging induces arginase activation and reduces nitric oxide (NO) production in the arteries. Intermittent hypoxia (IH), conferred by cycles of brief hypoxia and normoxia, contributes to OSAS pathogenesis. Here, we studied the role of arginase and aging in the pathogenesis of PAH in adult (9-mo-old) and young (2-mo-old) male Sprague-Dawley rats subjected to IH or normoxia for 4 weeks and analyzed them with a pressure-volume catheter inserted into the right ventricle (RV) and by pulsed Doppler echocardiography. Western blot analysis was conducted on arginase, NO synthase isoforms, and nitrotyrosine. IH induced PAH, as shown by increased RV systolic pressure and RV hypertrophy, in adult rats but not in young rats. IH increased expression levels of arginase I and II proteins in the adult rats. IH also increased arginase I expression in the pulmonary artery endothelium and arginase II in the pulmonary artery adventitia. Furthermore, IH reduced pulmonary levels of nitrate and nitrite but increased nitrotyrosine levels in adult rats. An arginase inhibitor (N(ω)-hydroxy-nor-1-arginine) prevented IH-induced PAH and normalized nitrite and nitrate levels in adult rats. IH induced arginase up-regulation and PAH in adult rats, but not in young rats, through reduced NO production. Our findings suggest that arginase inhibition prevents or reverses PAH. PMID:25490411

  9. Chronic active gastritis due to Helicobacter pylori in immunized gnotobiotic piglets.

    PubMed

    Eaton, K A; Krakowka, S

    1992-11-01

    In gnotobiotic piglets, parenteral vaccination with formalin-killed Helicobacter pylori and oral vaccination with live bacteria induced H. pylori-specific serum immunoglobulins G, M, and A. Vaccination reduced but did not prevent infection by subsequent challenge with viable H. pylori. Oral vaccination with killed bacteria was less effective in inducing serum antibody and had no effect on bacterial colonization. Immunization status influenced the histologic response of piglets to challenge by H. pylori. Lymphoplasmacytic gastritis was more severe in parenterally vaccinated piglets than in the other groups. In addition, neutrophilic infiltrates and neutrophilic gland abscesses in the gastric mucosa were present in 5 of 7 parenterally immunized piglets, none of the orally immunized piglets, and only 1 of 8 infected nonimmune control piglets. Furthermore, there was a positive correlation between immunoglobulin G, M, and A titer at challenge and severity of both neutrophilic and lymphocytic inflammation. These results suggest that although vaccination does not prevent infection by H. pylori, infection of an immune host leads to increased severity and activity of gastritis.

  10. Lateral OFC activity predicts decision bias due to first impressions during ultimatum games.

    PubMed

    Kim, Hackjin; Choi, Min-Jo; Jang, In-Ji

    2012-02-01

    Despite the prevalence and potentially harmful consequences of first impression bias during social decision-making, its precise neural underpinnings remain unclear. Here, on the basis of the fMRI study using ultimatum games, the authors show that the responders' decisions to accept or reject offers were significantly affected by facial trustworthiness of proposers. Analysis using a model-based fMRI method revealed that activity in the right lateral OFC (lOFC) of responders increased as a function of negative decision bias, indicating a greater likelihood of rejecting otherwise fair offers, possibly because of the facial trustworthiness of proposers. In addition, lOFC showed changes in functional connectivity strength with amygdala and insula as a function of decision bias, and individual differences in the strengths of connectivities between lOFC and bilateral insula were also found to predict the likelihood of responders to reject offers from untrustworthy-looking proposers. The present findings emphasize that the lOFC plays a pivotal role in integrating signals related to facial impression and creating signal biasing decisions during social interactions.

  11. Monitoring the Perturbation of Soil and Groundwater Microbial Communities Due to Pig Production Activities

    PubMed Central

    Hong, Pei-Ying; Yannarell, Anthony C.; Dai, Qinghua; Ekizoglu, Melike

    2013-01-01

    This study aimed to determine if biotic contaminants originating from pig production farms are disseminated into soil and groundwater microbial communities. A spatial and temporal sampling of soil and groundwater in proximity to pig production farms was conducted, and quantitative PCR (Q-PCR) was utilized to determine the abundances of tetracycline resistance genes (i.e., tetQ and tetZ) and integrase genes (i.e., intI1 and intI2). We observed that the abundances of tetZ, tetQ, intI1, and intI2 in the soils increased at least 6-fold after manure application, and their abundances remained elevated above the background for up to 16 months. Q-PCR further determined total abundances of up to 5.88 × 109 copies/ng DNA for tetZ, tetQ, intI1, and intI2 in some of the groundwater wells that were situated next to the manure lagoon and in the facility well used to supply water for one of the farms. We further utilized 16S rRNA-based pyrosequencing to assess the microbial communities, and our comparative analyses suggest that most of the soil samples collected before and after manure application did not change significantly, sharing a high Bray-Curtis similarity of 78.5%. In contrast, an increase in Bacteroidetes and sulfur-oxidizing bacterial populations was observed in the groundwaters collected from lagoon-associated groundwater wells. Genera associated with opportunistic human and animal pathogens, such as Acinetobacter, Arcobacter, Yersinia, and Coxiella, were detected in some of the manure-treated soils and affected groundwater wells. Feces-associated bacteria such as Streptococcus, Erysipelothrix, and Bacteroides were detected in the manure, soil, and groundwater ecosystems, suggesting a perturbation of the soil and groundwater environments by invader species from pig production activities. PMID:23396341

  12. Behavioral sexual dimorphism in models of anxiety and depression due to changes in HPA axis activity.

    PubMed

    Kokras, Nikolaos; Dalla, Christina; Sideris, Antonios C; Dendi, Artemis; Mikail, Hudu G; Antoniou, Katerina; Papadopoulou-Daifoti, Zeta

    2012-01-01

    Anxiety and depression are considered as stress-related disorders, which present considerable sex differentiation. In animal models of anxiety and depression sex differences have been described and linked to the sexually dimorphic hypothalamus-pituitary-adrenals (HPA) axis. The present study aimed to adjust corticosterone, the main HPA axis stress hormone, in male and female adrenalectomized rats with oral (25 μg/ml) corticosterone replacement (ADXR). Subsequently we investigated the behavioral performance of ADXR rats in the open field, light/dark and forced swim test (FST). Male ADXR rats showed less anxiety-like behavior when compared to sham-operated controls, despite adequate corticosterone replacement. They further showed increased swimming and reduced climbing behavior in the FST, while immobility duration did not differ from sham-operated males. On the contrary, adrenalectomy and corticosterone replacement did not have significant effects on the female behavioral response. Females were generally more active and presented less anxiety-like behavior than males, while they exhibited higher depressive-like symptomatology in the FST. ADXR affected behavioral responses predominantly in males, which in turn modified sex differences in the behavioral profile. Females in proestrous and estrous did not differ from females in diestrous and methestrous in any measured behavioral response. Present results suggest that the male and not the female behavioral responses in models of anxiety and depression were mainly affected by ADXR. These findings may play a significant role in explaining the differential coping strategy of the two sexes in response to stressful experiences. This article is part of a Special Issue entitled 'Anxiety and Depression'.

  13. 20 CFR 667.266 - What are the limitations related to religious activities?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Limitations related to sectarian activities are set forth at WIA section 188(a)(3) and 29 CFR 37.6(f). (b)(1) 29 CFR part 2, subpart D governs the circumstances under which DOL support, including WIA Title I.... See also 20 CFR 667.275 and 29 CFR 37.6(f)(1). 29 CFR part 2, subpart D also contains...

  14. 10 CFR 52.91 - Authorization to conduct limited work authorization activities.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... determination required by 10 CFR 50.10(e), and the Director of New Reactors or the Director of Nuclear Reactor... activities. 52.91 Section 52.91 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Combined Licenses § 52.91 Authorization to conduct limited...

  15. 10 CFR 52.91 - Authorization to conduct limited work authorization activities.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... determination required by 10 CFR 50.10(e), and the Director of New Reactors or the Director of Nuclear Reactor... activities. 52.91 Section 52.91 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Combined Licenses § 52.91 Authorization to conduct limited...

  16. 10 CFR 52.91 - Authorization to conduct limited work authorization activities.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... determination required by 10 CFR 50.10(e), and the Director of New Reactors or the Director of Nuclear Reactor... activities. 52.91 Section 52.91 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Combined Licenses § 52.91 Authorization to conduct limited...

  17. 10 CFR 52.91 - Authorization to conduct limited work authorization activities.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... determination required by 10 CFR 50.10(e), and the Director of New Reactors or the Director of Nuclear Reactor... activities. 52.91 Section 52.91 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Combined Licenses § 52.91 Authorization to conduct limited...

  18. 10 CFR 52.91 - Authorization to conduct limited work authorization activities.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... determination required by 10 CFR 50.10(e), and the Director of New Reactors or the Director of Nuclear Reactor... activities. 52.91 Section 52.91 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) LICENSES, CERTIFICATIONS, AND APPROVALS FOR NUCLEAR POWER PLANTS Combined Licenses § 52.91 Authorization to conduct limited...

  19. 26 CFR 1.103(n)-3T - Private activity bond limit (temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... Authority M has no private activity bond limit for 1987. Example 2. Under the laws of State U, only the... governmental unit that— (i) Enacts a specific law (e.g., a provision of a State constitution, charter, or... ceiling? A-11: A State, by law enacted at any time, may provide a different formula for allocating...

  20. Activity limitation and exertional dyspnea in adult asthmatic patients: What do we know?

    PubMed

    Vermeulen, François; Garcia, Gilles; Ninane, Vincent; Laveneziana, Pierantonio

    2016-08-01

    Limitation of activity is the most cited symptom described by uncontrolled asthma patients. Assessment of activity limitation can be undertaken through several ways, more or less complex, subjective or objective. Yet little is known about the link between patients sensations and objective measurements. The present review reports the current knowledge regarding activity limitation and symptom perception (i.e., exertional dyspnea) in adult patients with asthma. This work is based on references indexed by PubMed, irrespective of the year of publication. Overall, patients with stable asthma do not have a more sedentary lifestyle than healthy subjects. However, during a cycle ergometric test, the maximal load is reduced when FEV1, FVC and muscle strengths are decreased. Additionally, during the six-minute walking test, mild asthma patients walk less than healthy subjects even if the minimal clinically important difference is not reached. The major complaint of asthma patients when exercising is dyspnea that is mainly related to the inspiratory effort and also to dynamic hyperinflation in some circumstances. Finally, the administration of bronchodilator does not improve the ventilatory pattern and the exercise capacity of asthma patients and little is known on its effect on exertional dyspnea. The present review allows to conclude that until now there is no gold standard test allowing the objective assessment of "activity limitation and exertional dyspnea" in asthma patients. PMID:27492522

  1. 20 CFR 667.266 - What are the limitations related to religious activities?

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... LABOR ADMINISTRATIVE PROVISIONS UNDER TITLE I OF THE WORKFORCE INVESTMENT ACT Administrative Rules...) Limitations related to sectarian activities are set forth at WIA section 188(a)(3) and 29 CFR 37.6(f). (b)(1) 29 CFR part 2, subpart D governs the circumstances under which DOL support, including WIA Title...

  2. 78 FR 12790 - Agency Information Collection Activities; Proposed Collection; Comments Requested: Limited...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-02-25

    ... From the Federal Register Online via the Government Publishing Office ] DEPARTMENT OF JUSTICE Bureau of Alcohol, Tobacco, Firearms, and Explosives Agency Information Collection Activities; Proposed Collection; Comments Requested: Limited Permittee Transaction Report ACTION: 30-Day Notice. The Department of Justice (DOJ), Bureau of...

  3. Gsα activity is reduced in erythrocyte membranes of patients with psedohypoparathyroidism due to epigenetic alterations at the GNAS locus.

    PubMed

    Zazo, Celia; Thiele, Susanne; Martín, Cesar; Fernandez-Rebollo, Eduardo; Martinez-Indart, Lorea; Werner, Ralf; Garin, Intza; Hiort, Olaf; Perez de Nanclares, Guiomar

    2011-08-01

    In pseudohypoparathyroidism (PHP), PTH resistance results from impairment of signal transduction of G protein-coupled receptors caused by a deficiency of the Gsα-cAMP signaling cascade due to diminished Gsα activity in maternally imprinted tissues. In PHP-Ia, inactivating mutations of the GNAS gene lead to haploinsufficiency in some tissues with biallelic expression, so in addition to PHP, Albright's hereditary osteodystrophy (AHO) is also present. In PHP-Ib, caused by methylation defects at the GNAS locus, diminished Gsα activity was thought to be limited to maternally imprinted tissues, such as the renal proximal tubule and the thyroid, leading to a lack of AHO. Recently, we demonstrated methylation defects in patients with AHO signs, indicating a connection between epigenetic changes and AHO. Our objective was to determine Gsα activity in erythrocyte membranes in patients with epigenetic defects at the GNAS locus compared to normal controls and patients with inactivating GNAS mutations. Gsα activity and expression, mutation of the GNAS locus, and methylation status were studied in patients with PHP and mild signs of AHO (PHP-Ia: 12; PHP-Ib: 17, of which 8 had some features of AHO). Then, we statistically compared the Gsα activity of the different PHP subtypes. Patients with methylation defects at the GNAS locus show a significant decrease in erythrocyte Gsα activity compared to normal controls (PHP-Ib versus controls, p < .001). This was significantly lower in patients with AHO signs (PHP-Ib + mild-AHO versus PHP-Ib, p < .05). Our research shows that PHP-Ia and PHP-Ib classification is not only overlapped genetically, as reported, but also in terms of Gsα activity. Reduced expression of GNAS due to methylation defects could downregulate Gsα activity in other tissues beyond those described and could also be causative of AHO.

  4. Recognizing a limitation of the TBLC-activated peroxide system on low-temperature cotton bleaching.

    PubMed

    Chen, Wenhua; Wang, Lun; Wang, Dong; Zhang, Jingjing; Sun, Chang; Xu, Changhai

    2016-04-20

    In this study, cotton was bleached at low temperatures with an activated peroxide system which was established by incorporating a bleach activator, namely, N-[4-(triethylammoniomethyl)benzoyl]caprolactam chloride (TBCC) into an aqueous solution of hydrogen peroxide (H2O2). Experimental results showed that the bleaching performance was unexpectedly diminished as the TBCC concentration was increased over the range of 25-100g/L. Kinetic adsorption experiment indicated that this was most likely ascribed to the adsorptive interactions of TBCC and the in situ-generated compounds with cotton fibers. Such a limitation was especially fatal to cold pad-batch bleaching process of cotton in which a high TBCC concentration was often required. The results of this study may stimulate further research to avoid or overcome the limitation of the TBCC-activated peroxide system on low-temperature cotton bleaching.

  5. Hard magnetohydrodynamic limit in 1/3 sawtooth like activity in LHD

    SciTech Connect

    Varela, J.; Watanabe, K. Y.; Ohdachi, S.; Narushima, Y.

    2014-03-15

    The optimization of LHD discharges in inward-shifted configurations with 1/3 sawtooth like activity is an open issue. These relaxation events limit the LHD performance driving a periodic plasma deconfinement. The aim of this study is to analyze the 1/3 sawtooth like activity in plasmas with different stability properties to foreseen the best operation conditions and minimize its undesired effects. We summarize the results of several MHD simulations for plasmas with Lundquist numbers between 10{sup 5} and 10{sup 6} in the slow reconnection regime, studying the equilibria properties during the onset of a chain of 1/3 sawtooth like events. The research conclusions point out that the hard MHD limit can be reached in the inner plasma region after the onset of a strong 1/3 resonant sawtooth like event and trigger a plasma collapse. The collapse can be avoided if the system remains in the soft MHD limit, namely, in a regime with a pressure gradient and a magnetic turbulence below the critical values to drive the soft-hard MHD transition. In the soft MHD limit the system relaxations are the non resonant 1/3 sawtooth like events or a weak version of the 1/3 resonant sawtooth like events. A system relaxation in the soft MHD regime drives a minor plasma deconfinement that does not limit the LHD performance if the event periodicity is not very high.

  6. Physiological Characterization of Pseudomonas aeruginosa during Exotoxin A Synthesis: Glutamate, Iron Limitation, and Aconitase Activity

    PubMed Central

    Somerville, Greg; Mikoryak, Carole Ann; Reitzer, Larry

    1999-01-01

    Glutamate enhances the yield of exotoxin A (ETA), which is induced by iron limitation, from Pseudomonas aeruginosa. We tested the possibility that glutamate affects growth during iron restriction. We confirmed that iron limitation caused early entry into stationary phase but had no effect on the exponential growth rate. We showed that glutamate, as well as citrate and isocitrate, partially overcame this growth limitation. Glutamate had no effect on toxA (ETA-encoding) transcription, which implies that glutamate primarily increases the number of toxin-producing cells. In contrast, citrate and isocitrate diminished toxA transcription. Since glutamate, citrate, and isocitrate stimulated growth, we suspected a block in the citric acid cycle. Iron limitation reduced the activity of the iron-containing aconitase 12-fold but had no effect on isocitrate dehydrogenase activity, which was assayed as a control. There is a reciprocal relationship between aconitase activity and ETA synthesis, and this correlation does not appear to be coincidental because aconitase-specific effectors affect ETA synthesis. We tested whether a metabolic block is sufficient to induce ETA synthesis, but an aconitase-specific inhibitor diminished ETA production, which argues against this possibility. Finally, we present preliminary evidence that iron limitation may reversibly and posttranslationally inactivate aconitase in vivo. In summary, the environmental factors that stimulate ETA synthesis are related: glutamate bypasses an iron limitation-dependent metabolic block that causes entry into stationary phase. We speculate that one or more of the aconitases in P. aeruginosa may contribute to the control of virulence factor synthesis. PMID:9973331

  7. Tuning sensitivity of CAR to EGFR density limits recognition of normal tissue while maintaining potent anti-tumor activity

    PubMed Central

    Caruso, Hillary G.; Hurton, Lenka V.; Najjar, Amer; Rushworth, David; Ang, Sonny; Olivares, Simon; Mi, Tiejuan; Switzer, Kirsten; Singh, Harjeet; Huls, Helen; Lee, Dean A.; Heimberger, Amy B.; Champlin, Richard E.; Cooper, Laurence J. N.

    2015-01-01

    Many tumors over express tumor-associated antigens relative to normal tissue, such as epidermal growth factor receptor (EGFR). This limits targeting by human T cells modified to express chimeric antigen receptors (CARs) due to potential for deleterious recognition of normal cells. We sought to generate CAR+ T cells capable of distinguishing malignant from normal cells based on the disparate density of EGFR expression by generating two CARs from monoclonal antibodies which differ in affinity. T cells with low affinity Nimo-CAR selectively targeted cells over-expressing EGFR, but exhibited diminished effector function as the density of EGFR decreased. In contrast, the activation of T cells bearing high affinity Cetux-CAR was not impacted by the density of EGFR. In summary, we describe the generation of CARs able to tune T-cell activity to the level of EGFR expression in which a CAR with reduced affinity enabled T cells to distinguish malignant from non-malignant cells. PMID:26330164

  8. Factors That Moderate Activity Limitation and Participation Restriction in People With Multiple Sclerosis.

    PubMed

    Goverover, Yael; Strober, Lauren; Chiaravalloti, Nancy; DeLuca, John

    2015-01-01

    We examined the variables most associated with activity limitation (i.e., cooking) and participation restriction (i.e., employment) in 72 people with multiple sclerosis (MS). Participants underwent a comprehensive neuropsychological test battery assessing memory, executive functions, visual perception, and processing speed and completed questionnaires assessing activity, participation, fatigue, and affective symptoms. Results showed that processing speed was the only variable consistently significantly related to both activity and participation. When examining specific aspects of activity and participation in isolation, employment status was significantly associated with education level, visual memory, fatigue, and processing speed. Cooking ability was associated with performance on tasks of working memory, verbal memory, and processing speed. These findings suggest that processing speed is a primary cognitive factor in MS influencing quality of both activity and participation in everyday life. PMID:26122682

  9. Transform-limited pulses generated by an actively Q-switched distributed fiber laser.

    PubMed

    Cuadrado-Laborde, C; Pérez-Millán, P; Andrés, M V; Díez, A; Cruz, J L; Barmenkov, Yu O

    2008-11-15

    A single-mode, transform-limited, actively Q-switched distributed-feedback fiber laser is presented, based on a new in-line acoustic pulse generator. Our technique permits a continuous adjustment of the repetition rate that modulates the Q factor of the cavity. Optical pulses of 800 mW peak power, 32 ns temporal width, and up to 20 kHz repetition rates were obtained. The measured linewidth demonstrates that these pulses are transform limited: 6 MHz for a train of pulses of 10 kHz repetition rate, 80 ns temporal width, and 60 mW peak power. Efficient excitation of spontaneous Brillouin scattering is demonstrated.

  10. Effects of actuator limits in bifurcation control with applications to active control of fluid instabilities in turbomachinery

    NASA Astrophysics Data System (ADS)

    Wang, Yong

    Bifurcations are ubiquitous in engineering applications. Subcritical bifurcations are typically associated with hysteresis and catastrophic instability inception, while supercritical bifurcations are usually associated with gradual and more benign instability inception. With the assumption that the bifurcating modes are linearly unstabilizable, we give a constructive procedure of designing feedback laws to change the criticality of bifurcations from subcritical to supercritical. Algebraic necessary and sufficient conditions are obtained under which the criticality of a simple steady-state or Hopf bifurcation can be changed to supercritical by a smooth feedback. The effects of magnitude saturation, bandwidth, and rate limits are important issues in control engineering. We give qualitative estimates of the region of attraction to the stabilized bifurcating equilibrium/periodic orbits under these constraints. We apply the above theoretical results to the Moore-Greitzer model in active control of rotating stall and surge in gas turbine engines. Though linear stabilizability can be achieved using distributed actuation, it limits the practical usefulness due to considerations of affordability and reliability. On the other hand, simple but practically promising actuation schemes such as outlet bleed valves, a couple of air injectors, and magnetic bearings will make the system loss of linear stabilizability, thus the control design becomes a challenging task. The above mentioned theory in bifurcation stabilization can be applied to these cases. We analyze the effects of magnitude and rate saturations in active control of rotating stall using bleed valves. Analytic formulas are obtained for the operability enhancement as a function of system parameters, noise level, and actuator magnitude and rate limits. The formulas give good qualitative predictions when compared with experiments. Our conclusion is that actuator magnitude and rate limits are serious limiting factors in

  11. Lysyl oxidase family activity promotes resistance of pancreatic ductal adenocarcinoma to chemotherapy by limiting the intratumoral anticancer drug distribution.

    PubMed

    Le Calvé, Benjamin; Griveau, Audrey; Vindrieux, David; Maréchal, Raphaël; Wiel, Clotilde; Svrcek, Magali; Gout, Johann; Azzi, Lamia; Payen, Léa; Cros, Jérôme; de la Fouchardière, Christelle; Dubus, Pierre; Guitton, Jérôme; Bartholin, Laurent; Bachet, Jean-Baptiste; Bernard, David

    2016-05-31

    Solid tumors often display chemotherapy resistance. Pancreatic ductal adenocarcinoma (PDAC) is the archetype of resistant tumors as current chemotherapies are inefficient. The tumor stroma and extracellular matrix (ECM) are key contributors to PDAC aggressiveness and to limiting the efficacy of chemotherapy. Lysyl oxidase (LOX) family members mediate collagen cross-linking and thus promote ECM stiffening. Our data demonstrate increased LOX, LOXL1, and LOXL2 expression in PDAC, and that the level of fibrillar collagen, which is directly dependent of LOX family activity, is an independent predictive biomarker of adjuvant "Gemcitabine-based chemotherapy" benefit. Experimentally in mice, increased LOX family activity through LOXL2 promotes chemoresistance. This effect of LOX family activity seems to be due to decreased gemcitabine intra-tumoral diffusion. This observation might be explained by increased fibrillar collagen and decreased vessel size observed in tumors with increased LOX family activity. In conclusion, our data support that LOX family activity is both a novel target to improve chemotherapy as well as a novel biomarker to predict gemcitabine benefit in PDAC. Beyond the PDAC, it is possible that targeting LOX family activity might improve efficacy of chemotherapies against different kinds of solid tumors.

  12. Lysyl oxidase family activity promotes resistance of pancreatic ductal adenocarcinoma to chemotherapy by limiting the intratumoral anticancer drug distribution

    PubMed Central

    Le Calvé, Benjamin; Maréchal, Raphaël; Wiel, Clotilde; Svrcek, Magali; Gout, Johann; Azzi, Lamia; Payen, Léa; Cros, Jérôme; de la Fouchardière, Christelle; Dubus, Pierre; Guitton, Jérôme; Bartholin, Laurent; Bachet, Jean-Baptiste; Bernard, David

    2016-01-01

    Solid tumors often display chemotherapy resistance. Pancreatic ductal adenocarcinoma (PDAC) is the archetype of resistant tumors as current chemotherapies are inefficient. The tumor stroma and extracellular matrix (ECM) are key contributors to PDAC aggressiveness and to limiting the efficacy of chemotherapy. Lysyl oxidase (LOX) family members mediate collagen cross-linking and thus promote ECM stiffening. Our data demonstrate increased LOX, LOXL1, and LOXL2 expression in PDAC, and that the level of fibrillar collagen, which is directly dependent of LOX family activity, is an independent predictive biomarker of adjuvant “Gemcitabine-based chemotherapy” benefit. Experimentally in mice, increased LOX family activity through LOXL2 promotes chemoresistance. This effect of LOX family activity seems to be due to decreased gemcitabine intra-tumoral diffusion. This observation might be explained by increased fibrillar collagen and decreased vessel size observed in tumors with increased LOX family activity. In conclusion, our data support that LOX family activity is both a novel target to improve chemotherapy as well as a novel biomarker to predict gemcitabine benefit in PDAC. Beyond the PDAC, it is possible that targeting LOX family activity might improve efficacy of chemotherapies against different kinds of solid tumors. PMID:27050073

  13. Changes in antioxidant and antiinflammatory activity of black bean (Phaseolus vulgaris L.) protein isolates due to germination and enzymatic digestion.

    PubMed

    López-Barrios, Lidia; Antunes-Ricardo, Marilena; Gutiérrez-Uribe, Janet A

    2016-07-15

    Germination is an inexpensive process to improve the nutritional properties of legumes. The effect of germinating black bean seeds on the production of cotyledon protein hydrolysates (CPH) with antioxidant and antiinflammatory activities was analyzed in this research. After simulated enzymatic digestion, the oxygen radical absorbance capacity (ORAC) of CPH obtained from germinated black beans was lower than that observed for raw cotyledons. There were no significant differences among CPH cellular antioxidant activities (CAA), except for the high CAA of the 120 min hydrolysate obtained from one day germinated black bean cotyledons. The most significant changes due to germination and enzymatic hydrolysis were observed for the inhibition of nitric oxide (NO) production in macrophages. The NO synthesis inhibition observed for raw CPH was reduced after simulated gastrointestinal digestion but for germinated samples the inhibition was doubled. Peptides derived from cell wall proteins produced during germination could be responsible of antiinflammatory activity. PMID:26948633

  14. Incomplete activation of Escherichia coli hemolysin (HlyA) due to mutations in the 3' region of hlyC.

    PubMed Central

    Guzmán-Verri, C; García, F; Arvidson, S

    1997-01-01

    Mutational analysis of the carboxy-terminal region of Escherichia coli HlyC was performed by site-directed mutagenesis. Replacement of residue Val-127 or Lys-129 reduced the activity of HlyC to about 30 or 60%, respectively, of that of the wild type, while replacement of Gly-128 reduced the activity to less than 1% of the wild-type level. Complete inactivation of HlyC was caused by a double mutation, replacement of Gly-128 with valine and of Lys-129 with isoleucine. Analysis of culture supernatants from mutants with reduced hemolytic activity by two-dimensional gel electrophoresis revealed the production and simultaneous secretion of nonacylated, monoacylated, and fully acylated HlyA forms, demonstrating impairment of the acylation reaction, possibly due to a decreased affinity of HlyC for the individual HlyA acylation sites. PMID:9294460

  15. Changes in antioxidant and antiinflammatory activity of black bean (Phaseolus vulgaris L.) protein isolates due to germination and enzymatic digestion.

    PubMed

    López-Barrios, Lidia; Antunes-Ricardo, Marilena; Gutiérrez-Uribe, Janet A

    2016-07-15

    Germination is an inexpensive process to improve the nutritional properties of legumes. The effect of germinating black bean seeds on the production of cotyledon protein hydrolysates (CPH) with antioxidant and antiinflammatory activities was analyzed in this research. After simulated enzymatic digestion, the oxygen radical absorbance capacity (ORAC) of CPH obtained from germinated black beans was lower than that observed for raw cotyledons. There were no significant differences among CPH cellular antioxidant activities (CAA), except for the high CAA of the 120 min hydrolysate obtained from one day germinated black bean cotyledons. The most significant changes due to germination and enzymatic hydrolysis were observed for the inhibition of nitric oxide (NO) production in macrophages. The NO synthesis inhibition observed for raw CPH was reduced after simulated gastrointestinal digestion but for germinated samples the inhibition was doubled. Peptides derived from cell wall proteins produced during germination could be responsible of antiinflammatory activity.

  16. Radiative forcing due to anthropogenic greenhouse gas emissions from Finland: methods for estimating forcing of a country or an activity.

    PubMed

    Monni, Suvi; Korhonen, Riita; Savolainen, Ilkka

    2003-03-01

    The objective of this study was to assess the radiative forcing due to Finnish anthropogenic greenhouse gas emissions in three scenarios. All the Kyoto Protocol gases, i.e., CO(2), CH(4), N(2)O, and fluorinated gases, were included. The calculations showed that forcing due to Finnish emissions will increase in the case of all gases except methane by the year 2100. In 1990, radiative forcing due to Finland's emission history of all Kyoto Protocol gases was 3.2 mW/m(2), of which 71% was due to carbon dioxide, 17% to methane, and the rest to nitrous oxide. In 1990 the share of fluorinated gases was negligible. The share of methane in radiative forcing is decreasing, whereas the shares of carbon dioxide and of fluorinated gases are increasing and that of nitrous oxide remains nearly constant. The nonlinear features concerning additional concentrations in the atmosphere and radiative forcing due to emissions caused by a single country or activity are also considered. Radiative forcing due to Finnish emissions was assessed with two different approaches, the marginal forcing approach and the averaged forcing approach. The impact of the so-called background scenario, i.e., the scenario for concentration caused by global emissions, was also estimated. The difference between different forcing models at its highest was 40%, and the averaged forcing approach appeared to be the more recommendable. The effect of background concentrations in the studied cases was up to 11%. Hence, the choice of forcing model and background scenario should be given particular attention.

  17. Limits on Achievable Dimensional and Photon Efficiencies with Intensity-Modulation and Photon-Counting Due to Non-Ideal Photon-Counter Behavior

    NASA Technical Reports Server (NTRS)

    Moision, Bruce; Erkmen, Baris I.; Farr, William; Dolinar, Samuel J.; Birnbaum, Kevin M.

    2012-01-01

    An ideal intensity-modulated photon-counting channel can achieve unbounded photon information efficiencies (PIEs). However, a number of limitations of a physical system limit the practically achievable PIE. In this paper, we discuss several of these limitations and illustrate their impact on the channel. We show that, for the Poisson channel, noise does not strictly bound PIE, although there is an effective limit, as the dimensional information efficiency goes as e[overline] e PIE beyond a threshold PIE. Since the Holevo limit is bounded in the presence of noise, this illustrates that the Poisson approximation is invalid at large PIE for any number of noise modes. We show that a finite transmitter extinction ratio bounds the achievable PIE to a maximum that is logarithmic in the extinction ratio. We show how detector jitter limits the ability to mitigate noise in the PPM signaling framework. We illustrate a method to model detector blocking when the number of detectors is large, and illustrate mitigation of blocking with spatial spreading and altering. Finally, we illustrate the design of a high photon efficiency system using state-of-the-art photo-detectors and taking all these effects into account.

  18. Socio-demographic, health-related and psychosocial correlates of fear of falling and avoidance of activity in community-living older persons who avoid activity due to fear of falling

    PubMed Central

    Kempen, Gertrudis IJM; van Haastregt, Jolanda CM; McKee, Kevin J; Delbaere, Kim; Zijlstra, GA Rixt

    2009-01-01

    Background Fear of falling and avoidance of activity are common in old age and are suggested to be (public) health problems of equal importance to falls. Earlier studies of correlates of fear of falling and avoidance of activity did hardly differentiate between severe and mild levels of fear of falling and avoidance of activity which may be relevant from clinical point of view. Furthermore, most studies focused only on socio-demographics and/or health-related variables and hardly incorporated an extensive range of potential correlates of fear of falling including psychosocial variables. This study analyzes the univariate and multivariate associations between five socio-demographic, seven health-related and six psychosocial variables and levels of fear of falling and avoidance of activity in older persons who avoid activity due to fear of falling. Methods Cross-sectional study in 540 community-living older people aged ≥ 70 years with at least mild fear of falling and avoidance of activity. Chi-squares, t-tests and logistics regression analyses were performed to study the associations between the selected correlates and both outcomes. Results Old age, female sex, limitations in activity of daily living, impaired vision, poor perceived health, chronic morbidity, falls, low general self-efficacy, low mastery, loneliness, feelings of anxiety and symptoms of depression were identified as univariate correlates of severe fear of falling and avoidance of activity. Female sex, limitations in activity of daily living and one or more falls in the previous six months correlated independently with severe fear of falling. Higher age and limitations in activity of daily living correlated independently with severe avoidance of activity. Conclusion Psychosocial variables did not contribute independently to the difference between mild and severe fear of falling and to the difference between mild and severe avoidance of activity due to fear of falling. Although knowledge about the

  19. Bifunctional enhancement of oxygen reduction reaction activity on Ag catalysts due to water activation on LaMnO3 supports in alkaline media.

    PubMed

    Park, Shin-Ae; Lee, Eun-Kyung; Song, Hannah; Kim, Yong-Tae

    2015-08-27

    Ag is considered to be one of the best candidates for oxygen reduction reaction electrocatalysts in alkaline media for application in various electrochemical energy devices. In this study, we demonstrate that water activation is a key factor in enhancing the ORR activity in alkaline media, unlike in acid environments. Ag supported on LaMnO3 having a high oxophilicity showed a markedly higher ORR activity than that on carbon with inert surfaces. Through various electrochemical tests, it was revealed that the origin of the enhanced ORR activity of Ag/LaMnO3 is the bifunctional effect mainly due to the water activation at the interface between Ag and LaMnO3. Furthermore, the ligand effect due to the charge transfer from Mn to Ag leads to the enhancement of both oxygen activation on Ag and water activation on Mn sites, and hence, an improvement in the ORR activity of Ag/LaMnO3. On the other hand, the strain effect based on the fine structure variation in the lattice was negligible. We therefore suggest that the employment of a co-catalyst or support with highly oxophilic nature and the maximization of the interface between catalyst and support should be considered in the design of electrocatalysts for the ORR in alkaline media.

  20. Feedback Activation of Leukemia Inhibitory Factor Receptor Limits Response to Histone Deacetylase Inhibitors in Breast Cancer.

    PubMed

    Zeng, Hanlin; Qu, Jia; Jin, Nan; Xu, Jun; Lin, Chenchu; Chen, Yi; Yang, Xinying; He, Xiang; Tang, Shuai; Lan, Xiaojing; Yang, Xiaotong; Chen, Ziqi; Huang, Min; Ding, Jian; Geng, Meiyu

    2016-09-12

    Histone deacetylase (HDAC) inhibitors have demonstrated clinical benefits in subtypes of hematological malignancies. However, the efficacy of HDAC inhibitors in solid tumors remains uncertain. This study takes breast cancer as a model to understand mechanisms accounting for limited response of HDAC inhibitors in solid tumors and to seek combination solutions. We discover that feedback activation of leukemia inhibitory factor receptor (LIFR) signaling in breast cancer limits the response to HDAC inhibition. Mechanistically, HDAC inhibition increases histone acetylation at the LIFR gene promoter, which recruits bromodomain protein BRD4, upregulates LIFR expression, and activates JAK1-STAT3 signaling. Importantly, JAK1 or BRD4 inhibition sensitizes breast cancer to HDAC inhibitors, implicating combination inhibition of HDAC with JAK1 or BRD4 as potential therapies for breast cancer. PMID:27622335

  1. Improvement of the antimicrobial and antioxidant activities of camel and bovine whey proteins by limited proteolysis.

    PubMed

    Salami, Maryam; Moosavi-Movahedi, Ali Akbar; Ehsani, Mohammad Reza; Yousefi, Reza; Haertlé, Thomas; Chobert, Jean-Marc; Razavi, Seyed Hadi; Henrich, Robert; Balalaie, Saeed; Ebadi, Seyed Ahmad; Pourtakdoost, Samineh; Niasari-Naslaji, Amir

    2010-03-24

    The compositions and structures of bovine and camel milk proteins are different, which define their functional and biological properties. The aim of this study was to investigate the effects of enzymatic hydrolysis of camel and bovine whey proteins (WPs) on their antioxidant and antimicrobial properties. After enzymatic treatment, both the antioxidant and the antimicrobial activities of bovine and camel WPs were improved. The significantly higher antioxidant activity of camel WPs and their hydrolysates as compared with that of bovine WPs and their hydrolysates may result from the differences in amounts and/or in accessibilities of antioxidant amino acid residues present in their primary structures and from the prevalence of alpha-lactalbumin and beta-lactoglobulin as proteolytic substrates in camel and bovine whey, respectively. The results of this study reveal differences in antimicrobial and antioxidant activities between WP hydrolysates of bovine and camel milk and the effects of limited proteolysis on these activities.

  2. Mass spectrometric characterization of limited proteolysis activity in human plasma samples under mild acidic conditions.

    PubMed

    Yang, Jingzhi; Röwer, Claudia; Koy, Cornelia; Ruß, Manuela; Rüger, Christopher P; Zimmermann, Ralf; von Fritschen, Uwe; Bredell, Marius; Finke, Juliane C; Glocker, Michael O

    2015-11-01

    We developed a limited proteolysis assay for estimating dynamics in plasma-borne protease activities using MALDI ToF MS analysis as readout. A highly specific limited proteolysis activity was elicited in human plasma by shifting the pH to 6. Mass spectrometry showed that two singly charged ion signals at m/z 2753.44 and m/z 2937.56 significantly increased in abundance under mild acidic conditions as a function of incubation time. For proving that a provoked proteolytic activity in mild acidic solution caused the appearance of the observed peptides, control measurements were performed (i) with pepstatin as protease inhibitor, (ii) with heat-denatured samples, (iii) at pH 1.7, and (iv) at pH 7.5. Mass spectrometric fragmentation analysis showed that the observed peptides encompass the amino acid sequences 1-24 and 1-26 from the N-terminus of human serum albumin. Investigations on peptidase specificities suggest that the two best candidates for the observed serum albumin cleavages are cathepsin D and E. Reproducibility, robustness, and sensitivity prove the potential of the developed limited proteolysis assay to become of clinical importance for estimating dynamics of plasma-borne proteases with respect to associated pathophysiological tissue conditions.

  3. A relativistic self-consistent model for studying enhancement of space charge limited field emission due to counter-streaming ions

    SciTech Connect

    Lin, M. C. Lu, P. S.; Chang, P. C.; Ragan-Kelley, B.; Verboncoeur, J. P.

    2014-02-15

    Recently, field emission has attracted increasing attention despite the practical limitation that field emitters operate below the Child-Langmuir space charge limit. By introducing counter-streaming ion flow to neutralize the electron charge density, the space charge limited field emission (SCLFE) current can be dramatically enhanced. In this work, we have developed a relativistic self-consistent model for studying the enhancement of SCLFE by a counter-streaming ion current. The maximum enhancement is found when the ion effect is saturated, as shown analytically. The solutions in non-relativistic, intermediate, and ultra-relativistic regimes are obtained and verified with 1-D particle-in-cell simulations. This self-consistent model is general and can also serve as a benchmark or comparison for verification of simulation codes, as well as extension to higher dimensions.

  4. Mild Airflow Limitation during N2 Sleep Increases K-complex Frequency and Slows Electroencephalographic Activity

    PubMed Central

    Nguyen, Chinh D.; Wellman, Andrew; Jordan, Amy S.; Eckert, Danny J.

    2016-01-01

    Study Objectives: To determine the effects of mild airflow limitation on K-complex frequency and morphology and electroencephalogram (EEG) spectral power. Methods: Transient reductions in continuous positive airway pressure (CPAP) during stable N2 sleep were performed to induce mild airflow limitation in 20 patients with obstructive sleep apnea (OSA) and 10 healthy controls aged 44 ± 13 y. EEG at C3 and airflow were measured in 1-min windows to quantify K-complex properties and EEG spectral power immediately before and during transient reductions in CPAP. The frequency and morphology (amplitude and latency of P200, N550 and N900 components) of K-complexes and EEG spectral power were compared between conditions. Results: During mild airflow limitation (18% reduction in peak inspiratory airflow from baseline, 0.38 ± 0.11 versus 0.31 ± 0.1 L/sec) insufficient to cause American Academy of Sleep Medicine-defined cortical arousal, K-complex frequency (9.5 ± 4.5 versus 13.7 ± 6.4 per min, P < 0.01), N550 amplitude (25 ± 3 versus 27 ± 3 μV, P < 0.01) and EEG spectral power (delta: 147 ± 48 versus 230 ± 99 μV2, P < 0.01 and theta bands: 31 ± 14 versus 34 ± 13 μV2, P < 0.01) significantly increased whereas beta band power decreased (14 ± 5 versus 11 ± 4 μV2, P < 0.01) compared to the preceding non flow-limited period on CPAP. K-complex frequency, morphology, and timing did not differ between patients and controls. Conclusion: Mild airflow limitation increases K-complex frequency, N550 amplitude, and spectral power of delta and theta bands. In addition to providing mechanistic insight into the role of mild airflow limitation on K-complex characteristics and EEG activity, these findings may have important implications for respiratory conditions in which airflow limitation during sleep is common (e.g., snoring and OSA). Citation: Nguyen CD, Wellman A, Jordan AS, Eckert DJ. Mild airflow limitation during N2 sleep increases k-complex frequency and slows

  5. Signal transducer and activator of transcription 3 limits Epstein-Barr virus lytic activation in B lymphocytes.

    PubMed

    Hill, Erik R; Koganti, Siva; Zhi, Jizu; Megyola, Cynthia; Freeman, Alexandra F; Palendira, Umaimainthan; Tangye, Stuart G; Farrell, Paul J; Bhaduri-McIntosh, Sumita

    2013-11-01

    Lytic activation of Epstein-Barr virus (EBV) is central to its life cycle and to most EBV-related diseases. However, not every EBV-infected B cell is susceptible to lytic activation. This lack of uniform susceptibility to lytic activation also directly impacts the success of viral oncolytic therapy for EBV cancers, yet determinants of susceptibility to lytic induction signals are not well understood. To determine if host factors influence susceptibility to EBV lytic activation, we developed a technique to separate lytic from refractory cells and reported that EBV lytic activation occurs preferentially in cells with lower levels of signal transducer and activator of transcription 3 (STAT3). Using this tool to detect single cells, we now extend the correlation between STAT3 and lytic versus refractory states to EBV-infected circulating B cells in patients with primary EBV infection, leading us to investigate whether STAT3 controls susceptibility to EBV lytic activation. In loss-of-function and gain-of-function studies in EBV-positive B lymphoma and lymphoblastoid cells, we found that the levels of functional STAT3 regulate susceptibility to EBV lytic activation. This prompted us to identify a pool of candidate cellular genes that might be regulated by STAT3 to limit EBV lytic activation. From this pool, we confirmed increases in transcript levels in refractory cells of a set of genes known to participate in transcription repression. Taken together, our findings place STAT3 at a critical crossroads between EBV latency and lytic activation, processes fundamental to EBV lymphomagenesis. PMID:23966384

  6. Signal transducer and activator of transcription 3 limits Epstein-Barr virus lytic activation in B lymphocytes.

    PubMed

    Hill, Erik R; Koganti, Siva; Zhi, Jizu; Megyola, Cynthia; Freeman, Alexandra F; Palendira, Umaimainthan; Tangye, Stuart G; Farrell, Paul J; Bhaduri-McIntosh, Sumita

    2013-11-01

    Lytic activation of Epstein-Barr virus (EBV) is central to its life cycle and to most EBV-related diseases. However, not every EBV-infected B cell is susceptible to lytic activation. This lack of uniform susceptibility to lytic activation also directly impacts the success of viral oncolytic therapy for EBV cancers, yet determinants of susceptibility to lytic induction signals are not well understood. To determine if host factors influence susceptibility to EBV lytic activation, we developed a technique to separate lytic from refractory cells and reported that EBV lytic activation occurs preferentially in cells with lower levels of signal transducer and activator of transcription 3 (STAT3). Using this tool to detect single cells, we now extend the correlation between STAT3 and lytic versus refractory states to EBV-infected circulating B cells in patients with primary EBV infection, leading us to investigate whether STAT3 controls susceptibility to EBV lytic activation. In loss-of-function and gain-of-function studies in EBV-positive B lymphoma and lymphoblastoid cells, we found that the levels of functional STAT3 regulate susceptibility to EBV lytic activation. This prompted us to identify a pool of candidate cellular genes that might be regulated by STAT3 to limit EBV lytic activation. From this pool, we confirmed increases in transcript levels in refractory cells of a set of genes known to participate in transcription repression. Taken together, our findings place STAT3 at a critical crossroads between EBV latency and lytic activation, processes fundamental to EBV lymphomagenesis.

  7. Limiting concentrations of activated mononucleotides necessary for poly(C)-directed elongation of oligoguanylates

    NASA Technical Reports Server (NTRS)

    Kanavarioti, A.; Chang, S.; Alberas, D. J.

    1990-01-01

    Selected imidazolide-activated nucleotides have been subjected to hydrolysis under conditions similar to those that favor their template-directed oligomerization. Rate constants of hydrolysis of the P-N bond in guanosine 5'-monophosphate 2-methylimidazolide (2-MeImpG) and in guanosine 5'-monophosphate imidazolide (ImpG), kh, have been determined in the presence/absence of magnesium ion as a function of temperature and polycytidylate [poly(C)] concentration. Using the rate constant of hydrolysis of 2-MeImpG and the rate constant of elongation, i.e., the reaction of an oligoguanylate with 2-MeImpG in the presence of poly(C) acting as template, the limiting concentration of 2-MeImpG necessary for oligonucleotide elongation to compete with hydrolysis can be calculated. The limiting concentration is defined as the initial concentration of monomer that results in its equal consumption by hydrolysis and by elongation. These limiting concentrations of 2-MeImpG are found to be 1.7 mM at 37 degrees C and 0.36 mM at 1 degrees C. Boundary conditions in the form of limiting concentration of activated nucleotide may be used to evaluate a prebiotic model for chemical synthesis of biopolymers. For instance, the limiting concentration of monomer can be used as a basis of comparison among catalytic, but nonenzymatic, RNA-type systems. We also determined the rate constant of dimerization of 2-MeImpG, k2 = 0.45 +/- 0.06 M-1 h-1 in the absence of poly(C), and 0.45 +/- 0.06 less than or equal to k2 less than or equal to 0.97 +/- 0.13 M-1 h-1 in its presence at 37 degrees C and pH 7.95.(ABSTRACT TRUNCATED AT 250 WORDS).

  8. Enhanced photocatalytic activity of ultra-high aspect ratio ZnO nanowires due to Cu induced defects

    NASA Astrophysics Data System (ADS)

    Pasupathi Sugavaneshwar, Ramu; Duy Dao, Thang; Nanda, Karuna Kar; Nagao, Tadaaki; Hishita, Shunichi; Sakaguchi, Isao

    2015-12-01

    We report the synthesis of ZnO nanowires in ambient air at 650°C by a single-step vapor transport method using two different sources Zn (ZnO nanowires-I) and Zn:Cu (ZnO nanowires-II). The Zn:Cu mixed source co-vaporize Zn with a small amount of Cu at temperatures where elemental Cu source does not vaporize. This method provides us a facile route for Cu doping into ZnO. The aspect ratio of the grown ZnO nanowires-II was found to be higher by more than five times compared ZnO nanowires-I. Photocatalytic activity was measured by using a solar simulator and its ultraviolet-filtered light. The ZnO nanowires-II shows higher catalytic activity due to increased aspect ratio and higher content of surface defects because of incorporation of Cu impurities.

  9. Health and safety economics: limitations of economic appraisal of occupational health services activities in Poland.

    PubMed

    Rydlewska-Liszkowska, Izabela

    2002-01-01

    Methods of economic appraisal developed for evaluating activities in health care system may as well be successfully used for evaluating occupational health service activities. This involves the problem of resources management and cost containment not only at the company level, but also at different managerial and institutional levels. The decision makers have to know what resources are spent on occupational health, what is the effectiveness and efficiency of investing in employees health. The key issue of good understanding of the theory and practice of economic appraisal is a precise definition of costs, effectiveness and benefits. Another important area is the identification of information sources and barriers of economic appraisal. The results of the project carried out by the Nofer Institute of Occupational Medicine have provided evidence that defining costs, effectiveness and benefits of preventive activities need to be developed. It becomes even more clear after an analysis of existing limitations of economic appraisal in Polish enterprises.

  10. Advantages and Limitations in using Active Remote Sensing Technology for Disaster Damage Assessment

    NASA Astrophysics Data System (ADS)

    Tauhidur Rahman, Muhammad

    2013-04-01

    Following any major natural or man-made disaster, rapid monitoring and assessment of infrastructures and environmental damages are essential for successful rescue and relief operations. While pre- and post-disaster data from passive remote sensing imageries have played a major role in assessing damages on a damage/no damage basis for over four decades, latest advances in active remote sensing technologies such as Radar and Lidar are also becoming quite useful. The goal of this paper is to first explain the basic theories and analytical techniques involved in using active remote sensing data for assessing damages following a major natural disaster. It will then discuss some of the advantages and limitations often faced by researchers and disaster management personnel when using data from these sensors. Finally, it will highlight how data from Lidar and other active sensors were used to assess damages from three recent major disasters.

  11. Texture of Nanocrystalline Nickel: Probing the Lower Size Limit of Dislocation Activity

    NASA Astrophysics Data System (ADS)

    Chen, Bin; Lutker, Katie; Raju, Selva Vennila; Yan, Jinyuan; Kanitpanyacharoen, Waruntorn; Lei, Jialin; Yang, Shizhong; Wenk, Hans-Rudolf; Mao, Ho-kwang; Williams, Quentin

    2012-12-01

    The size of nanocrystals provides a limitation on dislocation activity and associated stress-induced deformation. Dislocation-mediated plastic deformation is expected to become inactive below a critical particle size, which has been proposed to be between 10 and 30 nanometers according to computer simulations and transmission electron microscopy analysis. However, deformation experiments at high pressure on polycrystalline nickel suggest that dislocation activity is still operative in 3-nanometer crystals. Substantial texturing is observed at pressures above 3.0 gigapascals for 500-nanometer nickel and at greater than 11.0 gigapascals for 20-nanometer nickel. Surprisingly, texturing is also seen in 3-nanometer nickel when compressed above 18.5 gigapascals. The observations of pressure-promoted texturing indicate that under high external pressures, dislocation activity can be extended down to a few-nanometers-length scale.

  12. On the variation of the ionospheric potential due to large-scale radioactivity enhancement and solar activity

    NASA Astrophysics Data System (ADS)

    Slyunyaev, Nikolay N.; Mareev, Evgeny A.; Zhidkov, Artem A.

    2015-08-01

    Sensitivity of the global electric circuit (GEC) to variations of atmospheric conductivity and current sources is analyzed and discussed. When the undisturbed exponential conductivity profile is assumed all over the Earth, the most substantial changes in the ionospheric potential (IP) are caused by conductivity perturbations inside thunderstorms; if, in addition, conductivity reduction inside thunderstorms and nonelectrified clouds is assumed, the IP becomes less sensitive to conductivity perturbations; besides, the IP is even more sensitive to source current variations than to conductivity. Current source and voltage source descriptions of GEC generators are compared; it is shown that the IP variation may critically depend on the chosen description. As an application, the IP variation due to nuclear weapons testing is studied; it is shown that neither local nor global increase of conductivity in the stratosphere could alone explain the observed 40% IP increase in the 1960s; at the same time this increase might be accounted for by a 40% increase in the source current density or a 46% reduction of the conductivity inside thunderstorms, provided that it was not reduced initially. The IP variation due to solar activity and, in particular, due to solar modulation of galactic cosmic ray flux is also discussed and modeled, which required an adequate parameterization of the rate of atmospheric ion pair production over the solar cycle. It is estimated that the maximum IP variation on the scale of the solar cycle does not exceed 5% of the mean value, unless source current perturbations are taken into account.

  13. Is there a common water-activity limit for the three domains of life?

    PubMed Central

    Stevenson, Andrew; Cray, Jonathan A; Williams, Jim P; Santos, Ricardo; Sahay, Richa; Neuenkirchen, Nils; McClure, Colin D; Grant, Irene R; Houghton, Jonathan DR; Quinn, John P; Timson, David J; Patil, Satish V; Singhal, Rekha S; Antón, Josefa; Dijksterhuis, Jan; Hocking, Ailsa D; Lievens, Bart; Rangel, Drauzio E N; Voytek, Mary A; Gunde-Cimerman, Nina; Oren, Aharon; Timmis, Kenneth N; McGenity, Terry J; Hallsworth, John E

    2015-01-01

    Archaea and Bacteria constitute a majority of life systems on Earth but have long been considered inferior to Eukarya in terms of solute tolerance. Whereas the most halophilic prokaryotes are known for an ability to multiply at saturated NaCl (water activity (aw) 0.755) some xerophilic fungi can germinate, usually at high-sugar concentrations, at values as low as 0.650–0.605 aw. Here, we present evidence that halophilic prokayotes can grow down to water activities of <0.755 for Halanaerobium lacusrosei (0.748), Halobacterium strain 004.1 (0.728), Halobacterium sp. NRC-1 and Halococcus morrhuae (0.717), Haloquadratum walsbyi (0.709), Halococcus salifodinae (0.693), Halobacterium noricense (0.687), Natrinema pallidum (0.681) and haloarchaeal strains GN-2 and GN-5 (0.635 aw). Furthermore, extrapolation of growth curves (prone to giving conservative estimates) indicated theoretical minima down to 0.611 aw for extreme, obligately halophilic Archaea and Bacteria. These were compared with minima for the most solute-tolerant Bacteria in high-sugar (or other non-saline) media (Mycobacterium spp., Tetragenococcus halophilus, Saccharibacter floricola, Staphylococcus aureus and so on) and eukaryotic microbes in saline (Wallemia spp., Basipetospora halophila, Dunaliella spp. and so on) and high-sugar substrates (for example, Xeromyces bisporus, Zygosaccharomyces rouxii, Aspergillus and Eurotium spp.). We also manipulated the balance of chaotropic and kosmotropic stressors for the extreme, xerophilic fungi Aspergillus penicilloides and X. bisporus and, via this approach, their established water-activity limits for mycelial growth (∼0.65) were reduced to 0.640. Furthermore, extrapolations indicated theoretical limits of 0.632 and 0.636 aw for A. penicilloides and X. bisporus, respectively. Collectively, these findings suggest that there is a common water-activity limit that is determined by physicochemical constraints for the three domains of life. PMID:25500507

  14. Is there a common water-activity limit for the three domains of life?

    PubMed

    Stevenson, Andrew; Cray, Jonathan A; Williams, Jim P; Santos, Ricardo; Sahay, Richa; Neuenkirchen, Nils; McClure, Colin D; Grant, Irene R; Houghton, Jonathan Dr; Quinn, John P; Timson, David J; Patil, Satish V; Singhal, Rekha S; Antón, Josefa; Dijksterhuis, Jan; Hocking, Ailsa D; Lievens, Bart; Rangel, Drauzio E N; Voytek, Mary A; Gunde-Cimerman, Nina; Oren, Aharon; Timmis, Kenneth N; McGenity, Terry J; Hallsworth, John E

    2015-06-01

    Archaea and Bacteria constitute a majority of life systems on Earth but have long been considered inferior to Eukarya in terms of solute tolerance. Whereas the most halophilic prokaryotes are known for an ability to multiply at saturated NaCl (water activity (a(w)) 0.755) some xerophilic fungi can germinate, usually at high-sugar concentrations, at values as low as 0.650-0.605 a(w). Here, we present evidence that halophilic prokayotes can grow down to water activities of <0.755 for Halanaerobium lacusrosei (0.748), Halobacterium strain 004.1 (0.728), Halobacterium sp. NRC-1 and Halococcus morrhuae (0.717), Haloquadratum walsbyi (0.709), Halococcus salifodinae (0.693), Halobacterium noricense (0.687), Natrinema pallidum (0.681) and haloarchaeal strains GN-2 and GN-5 (0.635 a(w)). Furthermore, extrapolation of growth curves (prone to giving conservative estimates) indicated theoretical minima down to 0.611 aw for extreme, obligately halophilic Archaea and Bacteria. These were compared with minima for the most solute-tolerant Bacteria in high-sugar (or other non-saline) media (Mycobacterium spp., Tetragenococcus halophilus, Saccharibacter floricola, Staphylococcus aureus and so on) and eukaryotic microbes in saline (Wallemia spp., Basipetospora halophila, Dunaliella spp. and so on) and high-sugar substrates (for example, Xeromyces bisporus, Zygosaccharomyces rouxii, Aspergillus and Eurotium spp.). We also manipulated the balance of chaotropic and kosmotropic stressors for the extreme, xerophilic fungi Aspergillus penicilloides and X. bisporus and, via this approach, their established water-activity limits for mycelial growth (∼0.65) were reduced to 0.640. Furthermore, extrapolations indicated theoretical limits of 0.632 and 0.636 a(w) for A. penicilloides and X. bisporus, respectively. Collectively, these findings suggest that there is a common water-activity limit that is determined by physicochemical constraints for the three domains of life. PMID:25500507

  15. Employment and activity limitations among adults with chronic obstructive pulmonary disease--United States, 2013.

    PubMed

    Wheaton, Anne G; Cunningham, Timothy J; Ford, Earl S; Croft, Janet B

    2015-03-27

    Chronic obstructive pulmonary disease (COPD) is a group of progressive respiratory conditions, including emphysema and chronic bronchitis, characterized by airflow obstruction and symptoms such as shortness of breath, chronic cough, and sputum production. COPD is an important contributor to mortality and disability in the United States. Healthy People 2020 has several COPD-related objectives,* including to reduce activity limitations among adults with COPD. To assess the state-level prevalence of COPD and the association of COPD with various activity limitations among U.S. adults, CDC analyzed data from the 2013 Behavioral Risk Factor Surveillance System (BRFSS). Among U.S. adults in all 50 states, the District of Columbia (DC), and two U.S. territories, 6.4% (an estimated 15.7 million adults) had been told by a physician or other health professional that they have COPD. Adults who reported having COPD were more likely to report being unable to work (24.3% versus 5.3%), having an activity limitation caused by health problems (49.6% versus 16.9%), having difficulty walking or climbing stairs (38.4% versus 11.3%), or using special equipment to manage health problems (22.1% versus 6.7%), compared with adults without COPD. Smokers who have been diagnosed with COPD are encouraged to quit smoking, which can slow the progression of the disease and reduce mobility impairment. In addition, COPD patients should consider participation in a pulmonary rehabilitation program that combines patient education and exercise training to address barriers to physical activity, such as respiratory symptoms and muscle wasting.

  16. Is there a common water-activity limit for the three domains of life?

    PubMed

    Stevenson, Andrew; Cray, Jonathan A; Williams, Jim P; Santos, Ricardo; Sahay, Richa; Neuenkirchen, Nils; McClure, Colin D; Grant, Irene R; Houghton, Jonathan Dr; Quinn, John P; Timson, David J; Patil, Satish V; Singhal, Rekha S; Antón, Josefa; Dijksterhuis, Jan; Hocking, Ailsa D; Lievens, Bart; Rangel, Drauzio E N; Voytek, Mary A; Gunde-Cimerman, Nina; Oren, Aharon; Timmis, Kenneth N; McGenity, Terry J; Hallsworth, John E

    2015-06-01

    Archaea and Bacteria constitute a majority of life systems on Earth but have long been considered inferior to Eukarya in terms of solute tolerance. Whereas the most halophilic prokaryotes are known for an ability to multiply at saturated NaCl (water activity (a(w)) 0.755) some xerophilic fungi can germinate, usually at high-sugar concentrations, at values as low as 0.650-0.605 a(w). Here, we present evidence that halophilic prokayotes can grow down to water activities of <0.755 for Halanaerobium lacusrosei (0.748), Halobacterium strain 004.1 (0.728), Halobacterium sp. NRC-1 and Halococcus morrhuae (0.717), Haloquadratum walsbyi (0.709), Halococcus salifodinae (0.693), Halobacterium noricense (0.687), Natrinema pallidum (0.681) and haloarchaeal strains GN-2 and GN-5 (0.635 a(w)). Furthermore, extrapolation of growth curves (prone to giving conservative estimates) indicated theoretical minima down to 0.611 aw for extreme, obligately halophilic Archaea and Bacteria. These were compared with minima for the most solute-tolerant Bacteria in high-sugar (or other non-saline) media (Mycobacterium spp., Tetragenococcus halophilus, Saccharibacter floricola, Staphylococcus aureus and so on) and eukaryotic microbes in saline (Wallemia spp., Basipetospora halophila, Dunaliella spp. and so on) and high-sugar substrates (for example, Xeromyces bisporus, Zygosaccharomyces rouxii, Aspergillus and Eurotium spp.). We also manipulated the balance of chaotropic and kosmotropic stressors for the extreme, xerophilic fungi Aspergillus penicilloides and X. bisporus and, via this approach, their established water-activity limits for mycelial growth (∼0.65) were reduced to 0.640. Furthermore, extrapolations indicated theoretical limits of 0.632 and 0.636 a(w) for A. penicilloides and X. bisporus, respectively. Collectively, these findings suggest that there is a common water-activity limit that is determined by physicochemical constraints for the three domains of life.

  17. Active co-infection with HBV and/or HCV in South African HIV positive patients due for cancer therapy.

    PubMed

    Musyoki, Andrew M; Msibi, Thembeni L; Motswaledi, Mojakgomo H; Selabe, Selokela G; Monokoane, Tshweu S; Mphahlele, M Jeffrey

    2015-02-01

    Human immunodeficiency virus (HIV), Hepatitis B virus (HBV) and Hepatitis C virus (HCV) share routes of transmission. There is limited data on the incidence of active co-infection with HBV and/or HCV in cancer patients infected with HIV in Africa. This was a prospective study based on 34 patients with varied cancer diagnosis, infected with HIV and awaiting cancer therapy in South Africa. HIV viral load, CD4+ cell counts, Alanine-aminotransferase and aspartate aminotransferase levels were tested. Exposure to HBV and HCV was assessed serologically using commercial kits. Active HBV and/or HCV co-infection was detected using viral specific nested PCR assays. HCV 5'-UTR PCR products were sequenced to confirm active HCV infection. Active viral infection was detected in 64.7% of patients for HBV, 38.2% for HCV, and 29.4% for both HBV and HCV. Occult HBV infection was observed in 63.6% of the patients, while seronegative HCV infection was found in 30.8% of patients. In addition, CD4+ cell count < 350 cells/µl was not a risk factor for increased active HBV, HCV or both HBV and HCV co-infections. A total of 72.7%, 18.2% and 9.1% of the HCV sequences were assigned genotype 5, 1 and 4 respectively.The study revealed for the first time a high active HBV and/or HCV co-infection rate in cancer patients infected with HIV. The findings call for HBV and HCV testing in such patients, and where feasible, appropriate antiviral treatment be indicated, as chemotherapy or radiotherapy has been associated with reactivation of viral hepatitis and termination of cancer therapy. PMID:25156907

  18. Activation of the caudal anterior cingulate cortex due to task-related interference in an auditory Stroop paradigm.

    PubMed

    Haupt, Sven; Axmacher, Nikolai; Cohen, Michael X; Elger, Christian E; Fell, Juergen

    2009-09-01

    Successful information processing requires the focusing of attention on a certain stimulus property and the simultaneous suppression of irrelevant information. The Stroop task is a useful paradigm to study such attentional top-down control in the presence of interference. Here, we investigated the neural correlates of an auditory Stroop task using fMRI. Subjects focused either on tone pitch (relatively high or low; phonetic task) or on the meaning of a spoken word (high/low/good; semantic task), while ignoring the other stimulus feature. We differentiated between task-related (phonetic incongruent vs. semantic incongruent) and sensory-level interference (phonetic incongruent vs. phonetic congruent). Task-related interference activated similar regions as in visual Stroop tasks, including the anterior cingulate cortex (ACC) and the presupplementary motor-area (pre-SMA). More specifically, we observed that the very caudal/posterior part of the ACC was activated and not the dorsal/anterior region. Because identical stimuli but different task demands are compared in this contrast, it reflects conflict at a relatively high processing level. A more conventional contrast between incongruent and congruent phonetic trials was associated with a different cluster in the pre-SMA/ACC which was observed in a large number of previous studies. Finally, functional connectivity analysis revealed that activity within the regions activated in the phonetic incongruent vs. semantic incongruent contrast was more strongly interrelated during semantically vs. phonetically incongruent trials. Taken together, we found (besides activation of regions well-known from visual Stroop tasks) activation of the very caudal and posterior part of the ACC due to task-related interference in an auditory Stroop task. PMID:19180558

  19. Quantitative Raman Spectroscopy when the Signal-to-Noise is Below the Limit of Quantitation due to Fluorescence Interference: Advantages of a Moving Window Sequentially Shifted Excitation Approach.

    PubMed

    Marshall, Sarah; Cooper, John B

    2016-09-01

    Raman spectroscopy is a useful analytical tool. However, its application is often limited because shot noise from fluorescence obscures the Raman signal. In such cases, quantitative analysis is not possible when the signal-to-noise ratio (SNR) drops below two. A method is described for performing quantitative Raman spectroscopy that not only removes fluorescence backgrounds, but also results in a significant improvement in the SNR. The Raman data is extracted using a moving window sequentially shifted excitation algorithm. To demonstrate the capabilities of the method, a binary mixture of two analytes at varying concentrations is quantified in the presence of a highly fluorescent dye. Linear calibration plots were constructed and validated for the binary model using individual Raman peaks with SNR ranging from 0.073-12.6; r(2) values are greater than 0.96 in all cases, with all but the weakest peaks yielding values greater than 0.997. The presented method demonstrates a universal and autonomous approach for the quantitative analysis of highly fluorescent samples via Raman spectroscopy. The lower limit on the SNR ratio for quantitative Raman analysis with the described method is 0.1. In order to assess the effectiveness of the presented method, the entire set of experiments was also processed using the more common shifted excitation Raman difference spectroscopy (SERDS) approach. The advantages of the proposed method over SERDS are demonstrated for both the detection limit and the SNR of the processed spectra. PMID:27613308

  20. Delayed healing of a navicular stress fracture, following limited weight-bearing activity

    PubMed Central

    Robinson, Matthew; Fulcher, Mark

    2014-01-01

    This report describes a 21-year-old man, a semiprofessional football (soccer) player, with a navicular stress fracture. It highlights the difficulty in diagnosing the condition and the complications arising from inadequate management. The case discusses the optimal management of these stress fractures and the detrimental role of weight-bearing recovery. The diagnosis of navicular stress fractures is challenging, and a high index of suspicion is required. The available literature indicates that limited weightbearing is not an appropriate treatment for navicular stress injuries. Non-weight-bearing (NWB) cast immobilisation for 6–8 weeks appears to be the gold standard treatment; however, open reduction with internal fixation (ORIF) has similar success rates and an equal return-to-play time but should also be followed by a period of NWB. NWB cast immobilisation for 6 weeks remains a good second option at any time following failed limited weight-bearing activity. PMID:24618870

  1. Transform-limited pulses generated by an actively Q-switched distributed fiber laser.

    PubMed

    Cuadrado-Laborde, C; Pérez-Millán, P; Andrés, M V; Díez, A; Cruz, J L; Barmenkov, Yu O

    2008-11-15

    A single-mode, transform-limited, actively Q-switched distributed-feedback fiber laser is presented, based on a new in-line acoustic pulse generator. Our technique permits a continuous adjustment of the repetition rate that modulates the Q factor of the cavity. Optical pulses of 800 mW peak power, 32 ns temporal width, and up to 20 kHz repetition rates were obtained. The measured linewidth demonstrates that these pulses are transform limited: 6 MHz for a train of pulses of 10 kHz repetition rate, 80 ns temporal width, and 60 mW peak power. Efficient excitation of spontaneous Brillouin scattering is demonstrated. PMID:19015677

  2. Active starvation responses mediate antibiotic tolerance in biofilms and nutrient-limited bacteria.

    PubMed

    Nguyen, Dao; Joshi-Datar, Amruta; Lepine, Francois; Bauerle, Elizabeth; Olakanmi, Oyebode; Beer, Karlyn; McKay, Geoffrey; Siehnel, Richard; Schafhauser, James; Wang, Yun; Britigan, Bradley E; Singh, Pradeep K

    2011-11-18

    Bacteria become highly tolerant to antibiotics when nutrients are limited. The inactivity of antibiotic targets caused by starvation-induced growth arrest is thought to be a key mechanism producing tolerance. Here we show that the antibiotic tolerance of nutrient-limited and biofilm Pseudomonas aeruginosa is mediated by active responses to starvation, rather than by the passive effects of growth arrest. The protective mechanism is controlled by the starvation-signaling stringent response (SR), and our experiments link SR-mediated tolerance to reduced levels of oxidant stress in bacterial cells. Furthermore, inactivating this protective mechanism sensitized biofilms by several orders of magnitude to four different classes of antibiotics and markedly enhanced the efficacy of antibiotic treatment in experimental infections. PMID:22096200

  3. Suicidal ideation and its determinants in Korean adults: The role of physical activity and functional limitations.

    PubMed

    Park, S M

    2015-01-01

    The recognition of suicide as a major public health problem has suggested the need to identify risk factors that have implications for preventive intervention. In the suicidal process, suicidal ideation is a key stage in the pathway leading to eventual suicide. This study investigated the influence of physical activity and functional limitations on suicidal ideation among young and middle-aged adults in a high suicidal society. Data for the current study were obtained from the Fourth Korea National Health and Nutrition Examination Survey 2007-2009 (KNHANES), a cross-sectional study conducted by the Korea Centers for Disease Control and Prevention. The survey conducted face-to-face interviews with young adults (n = 2326) and middle-aged adults (n = 3396). Using multivariate logistic regression analysis, the relationship of physical activity and functional limitations with suicidal ideation in young and middle-aged adults was assessed. A notable outcome was that the absence of a regular walking was correlated with increased suicidal ideation in middle-aged women. The other major finding was that young women and middle-aged adults with functional limitations had a high rate of suicidal thoughts. Multiple intervention approaches, including informational, social and behavioural approaches, are needed to promote regular walking in middle-aged women. For instance, mass media campaigns, community walking groups and individually adapted health behaviour modification may provide opportunities for positive intervention. Additionally, another important public health implication from these findings is the need for a suicide-intervention support system that includes screening for suicide risk in healthcare settings, especially among young women with physical limitations. PMID:25434531

  4. Chronic stress and moderate physical exercise prompt widespread common activation and limited differential activation in specific brain regions.

    PubMed

    Kim, Tae-Kyung; Han, Pyung-Lim

    2016-10-01

    Chronic stress in rodents produces depressive behaviors, whereas moderate physical exercise counteracts stress-induced depressive behaviors. Chronic stress and physical exercise appear to produce such opposing effects by changing the neural activity of specific brain regions. However, the detailed mechanisms through which the two different types of stimuli regulate brain function in opposite directions are not clearly understood. In the present study, we attempted to explore the neuroanatomical substrates mediating stress-induced behavioral changes and anti-depressant effects of exercise by examining stimulus-dependent c-Fos induction in the brains of mice that were exposed to repeated stress or exercise in a scheduled manner. Systematic and integrated analyses of c-Fos expression profiles indicated that various brain areas, including the prelimbic cortex, lateral septal area, and paraventricular nuclei of hypothalamus were commonly and strongly activated by both stress and exercise, while the lateral habenula and hippocampus were identified as being preferentially activated by stress and exercise, respectively. Exercise-dependent c-Fos expression in all regions examined in the brain occurred in both glutamatergic and GABAergic neurons. These results suggest that chronic stress and moderate exercise produce counteractive effects on mood behaviors, along with prompting widespread common activation and limited differential activation in specific brain regions. PMID:27539656

  5. Chronic stress and moderate physical exercise prompt widespread common activation and limited differential activation in specific brain regions.

    PubMed

    Kim, Tae-Kyung; Han, Pyung-Lim

    2016-10-01

    Chronic stress in rodents produces depressive behaviors, whereas moderate physical exercise counteracts stress-induced depressive behaviors. Chronic stress and physical exercise appear to produce such opposing effects by changing the neural activity of specific brain regions. However, the detailed mechanisms through which the two different types of stimuli regulate brain function in opposite directions are not clearly understood. In the present study, we attempted to explore the neuroanatomical substrates mediating stress-induced behavioral changes and anti-depressant effects of exercise by examining stimulus-dependent c-Fos induction in the brains of mice that were exposed to repeated stress or exercise in a scheduled manner. Systematic and integrated analyses of c-Fos expression profiles indicated that various brain areas, including the prelimbic cortex, lateral septal area, and paraventricular nuclei of hypothalamus were commonly and strongly activated by both stress and exercise, while the lateral habenula and hippocampus were identified as being preferentially activated by stress and exercise, respectively. Exercise-dependent c-Fos expression in all regions examined in the brain occurred in both glutamatergic and GABAergic neurons. These results suggest that chronic stress and moderate exercise produce counteractive effects on mood behaviors, along with prompting widespread common activation and limited differential activation in specific brain regions.

  6. KCC2 activity is critical in limiting the onset and severity of status epilepticus.

    PubMed

    Silayeva, Liliya; Deeb, Tarek Z; Hines, Rochelle M; Kelley, Matt R; Munoz, Michaelanne B; Lee, Henry H C; Brandon, Nicholas J; Dunlop, John; Maguire, Jaime; Davies, Paul A; Moss, Stephen J

    2015-03-17

    The K(+)/Cl(-) cotransporter (KCC2) allows adult neurons to maintain low intracellular Cl(-) levels, which are a prerequisite for efficient synaptic inhibition upon activation of γ-aminobutyric acid receptors. Deficits in KCC2 activity are implicated in epileptogenesis, but how increased neuronal activity leads to transporter inactivation is ill defined. In vitro, the activity of KCC2 is potentiated via phosphorylation of serine 940 (S940). Here we have examined the role this putative regulatory process plays in determining KCC2 activity during status epilepticus (SE) using knockin mice in which S940 is mutated to an alanine (S940A). In wild-type mice, SE induced by kainate resulted in dephosphorylation of S940 and KCC2 internalization. S940A homozygotes were viable and exhibited comparable basal levels of KCC2 expression and activity relative to WT mice. However, exposure of S940A mice to kainate induced lethality within 30 min of kainate injection and subsequent entrance into SE. We assessed the effect of the S940A mutation in cultured hippocampal neurons to explore the mechanisms underlying this phenotype. Under basal conditions, the mutation had no effect on neuronal Cl(-) extrusion. However, a selective deficit in KCC2 activity was seen in S940A neurons upon transient exposure to glutamate. Significantly, whereas the effects of glutamate on KCC2 function could be ameliorated in WT neurons with agents that enhance S940 phosphorylation, this positive modulation was lost in S940A neurons. Collectively our results suggest that phosphorylation of S940 plays a critical role in potentiating KCC2 activity to limit the development of SE. PMID:25733865

  7. Drosophila actin-Capping Protein limits JNK activation by the Src proto-oncogene.

    PubMed

    Fernández, B G; Jezowska, B; Janody, F

    2014-04-17

    The Src family kinases c-Src, and its downstream effectors, the Rho family of small GTPases RhoA and Jun N-terminal kinase (JNK) have a significant role in tumorigenesis. In this report, using the Drosophila wing disc epithelium as a model system, we demonstrate that the actin-Capping Protein (CP) αβ heterodimer, which regulates actin filament (F-actin) polymerization, limits Src-induced apoptosis or tissue overgrowth by restricting JNK activation. We show that overexpressing Src64B drives JNK-independent loss of epithelial integrity and JNK-dependent apoptosis via Btk29A, p120ctn and Rho1. However, when cells are kept alive with the Caspase inhibitor P35, JNK acts as a potent inducer of proliferation via activation of the Yorkie oncogene. Reducing CP levels direct apoptosis of overgrowing Src64B-overexpressing tissues. Conversely, overexpressing capping protein inhibits Src64B and Rho1, but not Rac1-induced JNK signaling. CP requires the actin-binding domain of the α-subunit to limit Src64B-induced apoptosis, arguing that the control of F-actin mediates this effect. In turn, JNK directs F-actin accumulation. Moreover, overexpressing capping protein also prevents apoptosis induced by ectopic JNK expression. Our data are consistent with a model in which the control of F-actin by CP limits Src-induced apoptosis or tissue overgrowth by acting downstream of Btk29A, p120ctn and Rho1, but upstream of JNK. In turn, JNK may counteract the effect of CP on F-actin, providing a positive feedback, which amplifies JNK activation. We propose that cytoskeletal changes triggered by misregulation of F-actin modulators may have a significant role in Src-mediated malignant phenotypes during the early stages of cellular transformation.

  8. Evidence of 131I and (134,137)Cs activities in Bordeaux, France due to the Fukushima nuclear accident.

    PubMed

    Perrot, F; Hubert, Ph; Marquet, Ch; Pravikoff, M S; Bourquin, P; Chiron, H; Guernion, P-Y; Nachab, A

    2012-12-01

    Following the Fukushima nuclear accident, low-background gamma spectrometry measurements were performed with HPGe detectors at the PRISNA platform located at the CENBG laboratory in Bordeaux, France. Different kinds of samples were collected and measured between March 26 and May 14, 2011. The first fission product observed was (131)I with maximum activity values of 2.4 mBq/m(3) in atmospheric dusts in air, 3.5 Bq/L in rain water, 15 Bq/kg in grass and 0.9 Bq/L in cow milk. The (134,137)Cs isotopes were also detected in air and in grass at a maximum level of 0.2 mBq/m(3) and 0.7 Bq/kg respectively, around one order of magnitude less than (131)I activity, but they were below detection limits in the other samples. All these activity values were consistent with others measured in France by IRSN and were well below those reported in May 1986 after the Chernobyl accident. PMID:22257694

  9. The Recent Increase in North Atlantic Hurricane Activity: Is it a Cycle or is it due to Global Warming?

    NASA Astrophysics Data System (ADS)

    Chelliah, M.; Bell, G.

    2006-12-01

    There has been a noticeable increase in North Atlantic hurricane activity since 1995. The devastating 2005 hurricane season broke many records with 27 tropical storms (TS), 15 hurricanes (H) and four category-5 major hurricanes (MH). This season also featured a record 15 landfalling storms in the Atlantic basin and four landfalling US major hurricanes (MH, defined as categories 3-5 on the Saffir-Simpson scale). Since 1995, North Atlantic hurricane seasons have averaged 13.1 TS, 7.4 H and 3.7 MH and according to NOAA, 9 of the 11 seasons have been termed above normal (active) seasons except for the two El Nino years 1997 and 2002. Prior to 1995, the North Atlantic basin experienced an overall inactive hurricane era from about 1971 to 1994 with an average 7.8 TS, 4.5H and 1.5 MH. But, prior to this inactive era (1971-1994) during the decades of the 1950's and 1960's (and in fact back to 1930's but with less reliable data) a typical season averaged about 8.0 TS, 5.4 H and 2.8 MH. As can be seen from these numbers, the seasonal averages for the number of TS, H, and MH during the recent active period since 1995 are overall higher than those during the earlier active decades of the 1950's and 1960's. These are no major disputes in these numbers. But there are differing views in the scientific community on the causal mechanisms (attribution) behind the recent increase in the North Atlantic hurricane activity. One view suggests that the recent increase is a return of the active hurricane cycle experienced in the past (such as the 1950's and 60's) and the other view suggesting that the increase could be due to global warming. This talk will focus on explaining, at least an attempt to explain, why there has been an increase in the overall hurricane activity since 1995. Based on recent published studies conducted at the Climate Prediction Center and elsewhere, it will be demonstrated that the answers to the ongoing debate, at least in the North Atlantic basin, is not as

  10. Limited recovery of soil microbial activity after transient exposure to gasoline vapors.

    PubMed

    Modrzyński, Jakub J; Christensen, Jan H; Mayer, Philipp; Brandt, Kristian K

    2016-09-01

    During gasoline spills complex mixtures of toxic volatile organic compounds (VOCs) are released to terrestrial environments. Gasoline VOCs exert baseline toxicity (narcosis) and may thus broadly affect soil biota. We assessed the functional resilience (i.e. resistance and recovery of microbial functions) in soil microbial communities transiently exposed to gasoline vapors by passive dosing via headspace for 40 days followed by a recovery phase of 84 days. Chemical exposure was characterized with GC-MS, whereas microbial activity was monitored as soil respiration (CO2 release) and soil bacterial growth ([(3)H]leucine incorporation). Microbial activity was strongly stimulated and inhibited at low and high exposure levels, respectively. Microbial growth efficiency decreased with increasing exposure, but rebounded during the recovery phase for low-dose treatments. Although benzene, toluene, ethylbenzene and xylene (BTEX) concentrations decreased by 83-97% during the recovery phase, microbial activity in high-dose treatments did not recover and numbers of viable bacteria were 3-4 orders of magnitude lower than in control soil. Re-inoculation with active soil microorganisms failed to restore microbial activity indicating residual soil toxicity, which could not be attributed to BTEX, but rather to mixture toxicity of more persistent gasoline constituents or degradation products. Our results indicate a limited potential for functional recovery of soil microbial communities after transient exposure to high, but environmentally relevant, levels of gasoline VOCs which therefore may compromise ecosystem services provided by microorganisms even after extensive soil VOC dissipation. PMID:27376993

  11. Limits to sustained energy intake. XVI. Body temperature and physical activity of female mice during pregnancy.

    PubMed

    Gamo, Yuko; Bernard, Amelie; Mitchell, Sharon E; Hambly, Catherine; Al Jothery, Aqeel; Vaanholt, Lobke M; Król, Elzbieta; Speakman, John R

    2013-06-15

    Lactation is the most energy-demanding phase of mammalian reproduction, and lactation performance may be affected by events during pregnancy. For example, food intake may be limited in late pregnancy by competition for space in the abdomen between the alimentary tract and fetuses. Hence, females may need to compensate their energy budgets during pregnancy by reducing activity and lowering body temperature. We explored the relationships between energy intake, body mass, body temperature and physical activity throughout pregnancy in the MF1 mouse. Food intake and body mass of 26 females were recorded daily throughout pregnancy. Body temperature and physical activity were monitored every minute for 23 h a day by implanted transmitters. Body temperature and physical activity declined as pregnancy advanced, while energy intake and body mass increased. Compared with a pre-mating baseline period, mice increased energy intake by 56% in late pregnancy. Although body temperature declined as pregnancy progressed, this served mostly to reverse an increase between baseline and early pregnancy. Reduced physical activity may compensate the energy budget of pregnant mice but body temperature changes do not. Over the last 3 days of pregnancy, food intake declined. Individual variation in energy intake in the last phase of pregnancy was positively related to litter size at birth. As there was no association between the increase in body mass and the decline in intake, we suggest the decline was not caused by competition for abdominal space. These data suggest overall reproductive performance is probably not constrained by events during pregnancy. PMID:23720802

  12. Limits to sustained energy intake. XVI. Body temperature and physical activity of female mice during pregnancy.

    PubMed

    Gamo, Yuko; Bernard, Amelie; Mitchell, Sharon E; Hambly, Catherine; Al Jothery, Aqeel; Vaanholt, Lobke M; Król, Elzbieta; Speakman, John R

    2013-06-15

    Lactation is the most energy-demanding phase of mammalian reproduction, and lactation performance may be affected by events during pregnancy. For example, food intake may be limited in late pregnancy by competition for space in the abdomen between the alimentary tract and fetuses. Hence, females may need to compensate their energy budgets during pregnancy by reducing activity and lowering body temperature. We explored the relationships between energy intake, body mass, body temperature and physical activity throughout pregnancy in the MF1 mouse. Food intake and body mass of 26 females were recorded daily throughout pregnancy. Body temperature and physical activity were monitored every minute for 23 h a day by implanted transmitters. Body temperature and physical activity declined as pregnancy advanced, while energy intake and body mass increased. Compared with a pre-mating baseline period, mice increased energy intake by 56% in late pregnancy. Although body temperature declined as pregnancy progressed, this served mostly to reverse an increase between baseline and early pregnancy. Reduced physical activity may compensate the energy budget of pregnant mice but body temperature changes do not. Over the last 3 days of pregnancy, food intake declined. Individual variation in energy intake in the last phase of pregnancy was positively related to litter size at birth. As there was no association between the increase in body mass and the decline in intake, we suggest the decline was not caused by competition for abdominal space. These data suggest overall reproductive performance is probably not constrained by events during pregnancy.

  13. Capability and limitation study of the DDT passive-active neutron waste assay instrument

    SciTech Connect

    Nicholas, N.J.; Coop, K.L.; Estep, R.J.

    1992-05-01

    The differential-dieaway-technique passive-active neutron assay system is widely used by transuranic waste generators to certify their drummed waste for eventual shipment to the Waste Isolation Pilot Plant (WIPP). Stricter criteria being established for waste emplacement at the WIPP site has led to a renewed interest in improvements to and a better understanding of current nondestructive assay (NDA) techniques. Our study includes the effects of source position, extreme matrices, high neutron backgrounds, and source self-shielding to explore the system`s capabilities and limitations and to establish a basis for comparison with other NDA systems. 11 refs.

  14. Capability and limitation study of the DDT passive-active neutron waste assay instrument

    SciTech Connect

    Nicholas, N.J.; Coop, K.L.; Estep, R.J.

    1992-05-01

    The differential-dieaway-technique passive-active neutron assay system is widely used by transuranic waste generators to certify their drummed waste for eventual shipment to the Waste Isolation Pilot Plant (WIPP). Stricter criteria being established for waste emplacement at the WIPP site has led to a renewed interest in improvements to and a better understanding of current nondestructive assay (NDA) techniques. Our study includes the effects of source position, extreme matrices, high neutron backgrounds, and source self-shielding to explore the system's capabilities and limitations and to establish a basis for comparison with other NDA systems. 11 refs.

  15. Experimental evaluation of decrease in the activities of polyphosphate/glycogen-accumulating organisms due to cell death and activity decay in activated sludge.

    PubMed

    Hao, Xiaodi; Wang, Qilin; Cao, Yali; van Loosdrecht, Mark C M

    2010-06-15

    Decrease in bacterial activity (biomass decay) in activated sludge can result from cell death (reduction in the amount of active bacteria) and activity decay (reduction in the specific activity of active bacteria). The goal of this study was to experimentally differentiate between cell death and activity decay as the cause of decrease in bacterial activity. By means of measuring maximal anaerobic phosphate release rates, verifying membrane integrity by live/dead staining and verifying presence of 16S rRNA with fluorescence in situ hybridization (FISH), the decay rates and death rates of polyphosphate-accumulating organisms (PAOs) in a biological nutrient removal (BNR) system and a laboratory phosphate removing sequencing batch reactor (SBR) system were determined, respectively, under famine conditions. In addition, the decay rate and death rate of glycogen-accumulating organisms (GAOs) in a SBR system with an enrichment culture of GAOs were also measured under famine conditions. Hereto the maximal anaerobic volatile fatty acid uptake rates, live/dead staining, and FISH were used. The experiments revealed that in the BNR and enriched PAO-SBR systems, activity decay contributed 58% and 80% to the decreased activities of PAOs, and that cell death was responsible for 42% and 20% of decreases in their respective activities. In the enriched GAOs system, activity decay constituted a proportion of 74% of the decreased activity of GAOs, and cell death only accounted for 26% of the decrease of their activity.

  16. Limitation in tidal volume expansion partially determines the intensity of physical activity in COPD.

    PubMed

    Kortianou, Eleni A; Aliverti, Andrea; Louvaris, Zafeiris; Vasilopoulou, Maroula; Nasis, Ioannis; Asimakos, Andreas; Zakynthinos, Spyros; Vogiatzis, Ioannis

    2015-01-01

    In patients with chronic obstructive pulmonary disease (COPD), reduced levels of daily physical activity are associated with the degree of impairment in lung, peripheral muscle, and central hemodynamic function. There is, however, limited evidence as to whether limitations in tidal volume expansion also, importantly, determine daily physical activity levels in COPD. Eighteen consecutive patients with COPD [9 active (forced expiratory volume in 1 s, FEV1: 1.59 ± 0.64 l) with an average daily movement intensity >1.88 m/s(2) and 9 less active patients (FEV1: 1.16 ± 0.41 l) with an average intensity <1.88 m/s(2)] underwent a 4-min treadmill test at a constant speed corresponding to each individual patient's average movement intensity, captured by a triaxial accelerometer during a preceding 7-day period. When chest wall volumes, captured by optoelectronic plethysmography, were expressed relative to comparable levels of minute ventilation (ranging between 14.5 ± 4.3 to 33.5 ± 4.4 l/min), active patients differed from the less active ones in terms of the lower increase in end-expiratory chest wall volume (by 0.15 ± 0.17 vs. 0.45 ± 0.21 l), the greater expansion in tidal volume (by 1.76 ± 0.58 vs. 1.36 ± 0.24 l), and the larger inspiratory reserve chest wall volume (IRVcw: by 0.81 ± 0.25 vs. 0.39 ± 0.27 l). IRVcw (r(2) = 0.420), expiratory flow (r(2) change = 0.174), and Borg dyspnea score (r(2) change = 0.123) emerged as the best contributors, accounting for 71.7% of the explained variance in daily movement intensity. Patients with COPD exhibiting greater ability to expand tidal volume and to maintain adequate inspiratory reserve volume tend to be more physically active. Thus interventions aiming at mitigating restrictions on operational chest wall volumes are expected to enhance daily physical activity levels in COPD. PMID:25398190

  17. Ulysses observations of magnetic waves due to newborn interstellar pickup ions. II. Application of turbulence concepts to limiting wave energy and observability

    SciTech Connect

    Cannon, Bradford E.; Smith, Charles W.; Isenberg, Philip A.; Vasquez, Bernard J.; Joyce, Colin J.; Murphy, Neil; Nuno, Raquel G. E-mail: Charles.Smith@unh.edu E-mail: Bernie.Vasquez@unh.edu E-mail: Neil.Murphy@jpl.nasa.gov

    2014-06-01

    The low-frequency magnetic waves that arise from the isotropization of newborn interstellar pickup ions (PUIs) are reasonably well described by linear and quasi-linear kinetic theory in so far as those theories predict the wave frequency and polarization in the spacecraft frame. Those theories fail to describe the scarce observability of the waves. Quasilinear theory predicts that the wave power should accumulate over long periods of time as the relatively weak kinetic instability slowly adds power to the observed spectrum. At the same time it has been argued that the same wave energy must serve as a secondary source of thermal ion heating in the outer heliosphere once the initial turbulence is depleted. To the extent that turbulent transport of the wave energy acts against the spectrally confined accumulation of wave energy, turbulence should be a limiting factor in observability. We argue that turbulence does limit the observability of the waves and we use turbulence theory to predict the observed wave energy. We compare this prediction against a database of 502 wave observations attributed to newborn interstellar PUIs observed by the Ulysses spacecraft.

  18. 26 CFR 1.103(n)-4T - Elective carryforward of unused private activity bond limit (temporary).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... from being issued pursuant to such carryforward election. In addition, where a carryforward election is... unused private activity bond limit in order to provide a sports facility described in section 103(b)(4)(B). In addition, a governmental unit may elect to carry forward its unused private activity bond limit...

  19. Epileptic activity is a surrogate for an underlying etiology and stopping the activity has a limited impact on developmental outcome.

    PubMed

    Korff, Christian M; Brunklaus, Andreas; Zuberi, Sameer M

    2015-10-01

    The concept of epileptic encephalopathy is important in clinical practice, but its relevance to an individual must be assessed in the appropriate context. Except in rare situations, epileptic activity is a surrogate for an underlying etiology, and stopping the activity has a limited impact on developmental outcome. Labeling a group of epilepsies as "the epileptic encephalopathies," risks minimizing the impact of epileptic activity on cognition and behavior more widely in epilepsy. Similarly, describing the encephalopathy associated with many infantile onset epilepsies as "epileptic" may be misleading. Finally, concentrating on the epileptic activity alone and not considering the wider consequences of the underlying etiology on cognitive and behavioral development, may focus research efforts and the search for improved therapies on too narrow a target. Therefore, epileptic encephalopathies should not be considered as a specific group of epilepsies but, rather, the concept of epileptic encephalopathy should be applicable to all types of epilepsies and epilepsy syndromes, whenever it is relevant in the clinical course of a particular individual, at any age. PMID:26293471

  20. Use of the mannitol pathway in fructose fermentation of Oenococcus oeni due to limiting redox regeneration capacity of the ethanol pathway.

    PubMed

    Richter, Hanno; Hamann, Inka; Unden, Gottfried

    2003-04-01

    The heterolactic bacterium Oenococcus oeni ferments fructose by a mixed heterolactic/mannitol fermentation. For heterolactic fermentation of fructose, the phosphoketolase pathway is used. The excess NAD(P)H from the phosphoketolase pathway is reoxidized by fructose (yielding mannitol). It is shown here that, under conditions of C-limitation or decreased growth rates, fructose can be fermented by heterolactic fermentation yielding nearly stoichiometric amounts of lactate, ethanol and CO(2). Quantitative evaluation of NAD(P)H-producing (phosphoketolase pathway) and -reoxidizing (ethanol, mannitol and erythritol pathways) reactions demonstrated that at high growth rates or in batch cultures the ethanol pathway does not have sufficient capacity for NAD(P)H reoxidation, requiring additional use of the mannitol pathway to maintain the growth rate. In addition, insufficient capacities to reoxidize NAD(P)H causes inhibition of growth, whereas increased NAD(P)H reoxidation by electron acceptors such as pyruvate increases the growth rate.

  1. Disaggregating Activities of Daily Living Limitations for Predicting Nursing Home Admission

    PubMed Central

    Fong, Joelle H; Mitchell, Olivia S; Koh, Benedict S K

    2015-01-01

    Objective To examine whether disaggregated activities of daily living (ADL) limitations better predict the risk of nursing home admission compared to conventionally used ADL disability counts. Data Sources We used panel data from the Health and Retirement Study (HRS) for years 1998–2010. The HRS is a nationally representative survey of adults older than 50 years (n = 18,801). Study Design We fitted Cox regressions in a continuous time survival model with age at first nursing home admission as the outcome. Time-varying ADL disability types were the key explanatory variables. Principal Findings Of the six ADL limitations, bathing difficulty emerged as the strongest predictor of subsequent nursing home placement across cohorts. Eating and dressing limitations were also influential in driving admissions among more recent cohorts. Using simple ADL counts for analysis yielded similar adjusted R2s; however, the amount of explained variance doubled when we allowed the ADL disability measures to time-vary rather than remain static. Conclusions Looking beyond simple ADL counts can provide health professionals insights into which specific disability types trigger long-term nursing home use. Functional disabilities measured closer in time carry more prognostic power than static measures. PMID:25256014

  2. Differential activity in Heschl's gyrus between deaf and hearing individuals is due to auditory deprivation rather than language modality.

    PubMed

    Cardin, Velia; Smittenaar, Rebecca C; Orfanidou, Eleni; Rönnberg, Jerker; Capek, Cheryl M; Rudner, Mary; Woll, Bencie

    2016-01-01

    Sensory cortices undergo crossmodal reorganisation as a consequence of sensory deprivation. Congenital deafness in humans represents a particular case with respect to other types of sensory deprivation, because cortical reorganisation is not only a consequence of auditory deprivation, but also of language-driven mechanisms. Visual crossmodal plasticity has been found in secondary auditory cortices of deaf individuals, but it is still unclear if reorganisation also takes place in primary auditory areas, and how this relates to language modality and auditory deprivation. Here, we dissociated the effects of language modality and auditory deprivation on crossmodal plasticity in Heschl's gyrus as a whole, and in cytoarchitectonic region Te1.0 (likely to contain the core auditory cortex). Using fMRI, we measured the BOLD response to viewing sign language in congenitally or early deaf individuals with and without sign language knowledge, and in hearing controls. Results show that differences between hearing and deaf individuals are due to a reduction in activation caused by visual stimulation in the hearing group, which is more significant in Te1.0 than in Heschl's gyrus as a whole. Furthermore, differences between deaf and hearing groups are due to auditory deprivation, and there is no evidence that the modality of language used by deaf individuals contributes to crossmodal plasticity in Heschl's gyrus. PMID:26348556

  3. Factors Predicting Nutrition and Physical Activity Behaviors Due to Cardiovascular Disease in Tehran University Students: Application of Health Belief Model

    PubMed Central

    Rahmati-Najarkolaei, Fatemeh; Tavafian, Sedigheh Sadat; Gholami Fesharaki, Mohammad; Jafari, Mohammad Reza

    2015-01-01

    Background: Disease preventing methods focus mostly on lifestyle factors such as physical activity, healthy diet and not smoking. Previous studies verified using theory and models to change unhealthy behaviors, so that health belief model (HBM) is a useful framework for describing the healthy nutrition behavior. Objectives: This study aimed to predict factors related to unhealthy nutrition and inactive life in students of Tehran University, Tehran, Iran based on the Health Belief Model (HBM). Patients and Methods: In this cross sectional study, proportional quota sampling from three different educational levels was conducted from October to December 2012. A self-administered validated instrument based on the Health Belief Model (HBM) with 69 items and four sections was used to collect data. In this study through using linear and logistic regression, the effect of body mass index, age, gender, marriage, self-efficacy, cues to action, knowledge, perceived severity, susceptibility, benefits and barriers on nutrition and physical activity behavior were assessed. SPSS version 18 was used to analyze data. Results: Totally, 368 students including 318 female students (86.4%) and 50 male students (13.6%) with a mean age of 24.9 years (SD = 4.55) took part in the study. Among all independent variables, gender (P < 0.001), knowledge (P = 0.023) and perceived barriers (P = 0.004) predicted nutrition behavior. In case of physical activity, knowledge (P = 0.011), perceived severity (P = 0.009), perceived barriers (P = 0.019) and self-efficacy (P = 0.033) had significance association with physical activity behavior. Conclusions: This study indicated that health belief model contrasts could predict the risky behavior of university students due to heart disease. However, more researches are needed to verify the predictors of high risky behaviors in students. PMID:26019896

  4. The Activity of Nodules of the Supernodulating Mutant Mtsunn Is not Limited by Photosynthesis under Optimal Growth Conditions

    PubMed Central

    Cabeza, Ricardo A.; Lingner, Annika; Liese, Rebecca; Sulieman, Saad; Senbayram, Mehmet; Tränkner, Merle; Dittert, Klaus; Schulze, Joachim

    2014-01-01

    Legumes match the nodule number to the N demand of the plant. When a mutation in the regulatory mechanism deprives the plant of that ability, an excessive number of nodules are formed. These mutants show low productivity in the fields, mainly due to the high carbon burden caused through the necessity to supply numerous nodules. The objective of this study was to clarify whether through optimal conditions for growth and CO2 assimilation a higher nodule activity of a supernodulating mutant of Medicago truncatula (M. truncatula) can be induced. Several experimental approaches reveal that under the conditions of our experiments, the nitrogen fixation of the supernodulating mutant, designated as sunn (super numeric nodules), was not limited by photosynthesis. Higher specific nitrogen fixation activity could not be induced through short- or long-term increases in CO2 assimilation around shoots. Furthermore, a whole plant P depletion induced a decline in nitrogen fixation, however this decline did not occur significantly earlier in sunn plants, nor was it more intense compared to the wild-type. However, a distinctly different pattern of nitrogen fixation during the day/night cycles of the experiment indicates that the control of N2 fixing activity of the large number of nodules is an additional problem for the productivity of supernodulating mutants. PMID:24727372

  5. The activity of nodules of the supernodulating mutant Mtsunn is not limited by photosynthesis under optimal growth conditions.

    PubMed

    Cabeza, Ricardo A; Lingner, Annika; Liese, Rebecca; Sulieman, Saad; Senbayram, Mehmet; Tränkner, Merle; Dittert, Klaus; Schulze, Joachim

    2014-04-10

    Legumes match the nodule number to the N demand of the plant. When a mutation in the regulatory mechanism deprives the plant of that ability, an excessive number of nodules are formed. These mutants show low productivity in the fields, mainly due to the high carbon burden caused through the necessity to supply numerous nodules. The objective of this study was to clarify whether through optimal conditions for growth and CO2 assimilation a higher nodule activity of a supernodulating mutant of Medicago truncatula (M. truncatula) can be induced. Several experimental approaches reveal that under the conditions of our experiments, the nitrogen fixation of the supernodulating mutant, designated as sunn (super numeric nodules), was not limited by photosynthesis. Higher specific nitrogen fixation activity could not be induced through short- or long-term increases in CO2 assimilation around shoots. Furthermore, a whole plant P depletion induced a decline in nitrogen fixation, however this decline did not occur significantly earlier in sunn plants, nor was it more intense compared to the wild-type. However, a distinctly different pattern of nitrogen fixation during the day/night cycles of the experiment indicates that the control of N2 fixing activity of the large number of nodules is an additional problem for the productivity of supernodulating mutants.

  6. [Survival by a young woman with malnutrition due to alcoholism and eating disorders and with acute respiratory distress syndrome due to severe pneumonia who showed increased serum neutrophil elastase activity].

    PubMed

    Nakajima, Hirokazu; Sawaguchi, Hirochiyo; Nakajima, Shigenori

    2006-11-01

    A 30-year-old woman with malnutrition due to alcoholism and eating disorders was found to have acute respiratory distress syndrome (ARDS) and sepsis due to severe Streptococcus pneumoniae pneumonia. S. pneumoniae was detected by an in vitro rapid immunochromatographic assay for S. pneumoniae antigen in urine on the day of admission and by blood culture 2 days after admission. Symptoms and laboratory findings improved after treatment with sivelestat sodium hydrate, antibiotics, and mechanical ventilation. Treatment with sivelestat sodium hydrate also decreased serum neutrophil elastase activity. This case demonstrates the usefulness of early treatment with sivelestat sodium hydrate in ARDS due to severe pneumonia.

  7. Relationship between activity limitations and participation restriction in school-aged children with cerebral palsy

    PubMed Central

    Park, Eun-Young; Kim, Won-Ho

    2015-01-01

    [Purpose] This study investigated the relationship between activity limitation and participation restriction in school-aged children with cerebral palsy. [Subjects and Methods] Data were collected from 109 children with cerebral palsy aged 6–12 years. Activity limitations were assessed by using functional classification systems including the Korean-Gross Motor Function Classification System, the Korean-Manual Ability Classification System, and the Korean-Communication Function Classification System. Participation restriction was measured using the Korean-Frequency of Participation Questionnaire. Physical or occupational therapists and parents collected the data. [Results] All levels of the functional classification systems were significantly negatively correlated with Korean-Frequency of Participation Questionnaire ratings (r= −0.382 to −0.477). The Korean-Frequency of Participation Questionnaire ratings differed significantly with respect to the functional classification systems; in particular, the differences in the ratings of levels I and V were significant. The Korean-Communication Function Classification System and Korean-Gross Motor Function Classification System were significant predictors of participation, explaining 26.5% of the variance. [Conclusion] Intervention programs are required to promote communication skills and gross motor ability in order to improve the participation of children with cerebral palsy. PMID:26357445

  8. Muscle Strength, Physical Activity, and Functional Limitations in Older Adults with Central Obesity

    PubMed Central

    Germain, Cassandra M.; Batsis, John A.; Vasquez, Elizabeth; McQuoid, Douglas R.

    2016-01-01

    Background. Obesity and muscle weakness are independently associated with increased risk of physical and functional impairment in older adults. It is unknown whether physical activity (PA) and muscle strength combined provide added protection against functional impairment. This study examines the association between muscle strength, PA, and functional outcomes in older adults with central obesity. Methods. Prevalence and odds of physical (PL), ADL, and IADL limitation were calculated for 6,388 community dwelling adults aged ≥ 60 with central obesity. Individuals were stratified by sex-specific hand grip tertiles and PA. Logistic models were adjusted for age, education, comorbidities, and body-mass index and weighted. Results. Overall prevalence of PL and ADL and IADL limitations were progressively lower by grip category. Within grip categories, prevalence was lower for individuals who were active than those who were inactive. Adjusted models showed significantly lower odds of PL OR 0.42 [0.31, 0.56]; ADL OR 0.60 [0.43, 0.84], and IADL OR 0.46 [0.35, 0.61] for those in the highest grip strength category as compared to those in the lowest grip category. Conclusion. Improving grip strength in obese elders who are not able to engage in traditional exercise is important for reducing odds of physical and functional impairment. PMID:27034833

  9. Systematic Expansion of Active Spaces beyond the CASSCF Limit: A GASSCF/SplitGAS Benchmark Study.

    PubMed

    Vogiatzis, Konstantinos D; Li Manni, Giovanni; Stoneburner, Samuel J; Ma, Dongxia; Gagliardi, Laura

    2015-07-14

    The applicability and accuracy of the generalized active space self-consistent field, (GASSCF), and (SplitGAS) methods are presented. The GASSCF method enables the exploration of larger active spaces than with the conventional complete active space SCF, (CASSCF), by fragmentation of a large space into subspaces and by controlling the interspace excitations. In the SplitGAS method, the GAS configuration interaction, CI, expansion is further partitioned in two parts: the principal, which includes the most important configuration state functions, and an extended, containing less relevant but not negligible ones. An effective Hamiltonian is then generated, with the extended part acting as a perturbation to the principal space. Excitation energies of ozone, furan, pyrrole, nickel dioxide, and copper tetrachloride dianion are reported. Various partitioning schemes of the GASSCF and SplitGAS CI expansions are considered and compared with the complete active space followed by second-order perturbation theory, (CASPT2), and multireference CI method, (MRCI), or available experimental data. General guidelines for the optimum applicability of these methods are discussed together with their current limitations. PMID:26575738

  10. 1-Aminocyclopropane-1-Carboxylate Oxidase Activity Limits Ethylene Biosynthesis in Rumex palustris during Submergence

    PubMed Central

    Vriezen, Wim H.; Hulzink, Raymond; Mariani, Celestina; Voesenek, Laurentius A.C.J.

    1999-01-01

    Submergence strongly stimulates petiole elongation in Rumex palustris, and ethylene accumulation initiates and maintains this response in submerged tissues. cDNAs from R. palustris corresponding to a 1-aminocyclopropane-1-carboxylate (ACC) oxidase gene (RP-ACO1) were isolated from elongating petioles and used to study the expression of the corresponding gene. An increase in RP-ACO1 messenger was observed in the petioles and lamina of elongating leaves 2 h after the start of submergence. ACC oxidase enzyme activity was measured in homogenates of R. palustris shoots, and a relevant increase was observed within 12 h under water with a maximum after 24 h. We have shown previously that the ethylene production rate of submerged shoots does not increase significantly during the first 24 h of submergence (L.A.C.J. Voesenek, M. Banga, R.H. Thier, C.M. Mudde, F.M. Harren, G.W.M. Barendse, C.W.P.M. Blom [1993] Plant Physiol 103: 783–791), suggesting that under these conditions ACC oxidase activity is inhibited in vivo. We found evidence that this inhibition is caused by a reduction of oxygen levels. We hypothesize that an increased ACC oxidase enzyme concentration counterbalances the reduced enzyme activity caused by low oxygen concentration during submergence, thus sustaining ethylene production under these conditions. Therefore, ethylene biosynthesis seems to be limited at the level of ACC oxidase activity rather than by ACC synthase in R. palustris during submergence. PMID:10482674

  11. Three active galactic nuclei close to the effective Eddington limit for dusty gas

    NASA Astrophysics Data System (ADS)

    Vasudevan, R. V.; Fabian, A. C.; Mushotzky, R. F.; Meléndez, M.; Winter, L. M.; Trippe, M. L.

    2013-06-01

    The effective Eddington limit for dusty gas surrounding active galactic nucleus (AGN) is lower than the canonical Eddington limit for hydrogen gas. Previous results from the Swift/Burst Alert Telescope 9-month catalogue suggested that in the overwhelming majority of local AGN, the dusty absorbing gas is below this effective Eddington limit, implying that radiation pressure is insufficient to blow away the absorbing clouds. We present an analysis of three objects from that sample which were found to be close to the effective Eddington limit (NGC 454, 2MASX J03565655-4041453 and XSS J05054-2348), using newly obtained XMM-Newton data. We use the X-ray data to better constrain the absorbing column density, and supplement them with XMM Optical Monitor data, infrared Spitzer and Herschel data were available to construct a broad-band spectral energy distribution to estimate refined bolometric luminosities and Eddington ratios for these three objects. The new XMM-Newton observations show all three objects moving away from the region expected for short-lived absorption in the NH-λEdd plane into the `long-lived absorption' region. We find our conclusions robust to different methods for estimating the bolometric luminosity and Eddington ratio. Interestingly, 2MASX J03565655-4041453 and XSS J05054-2348 now exhibit complex X-ray spectra, at variance with previous analyses of their Swift/X-Ray Telescope data. We find evidence for absorption variability in NGC 454 and 2MASX J03565655-4041453, perhaps implying that although the radiation pressure from the central engine is insufficient to cause clearly detectable outflows, it may cause absorption variations over longer time-scales. However, more robust black hole mass estimates would improve the accuracy of the Eddington ratio estimates for these objects.

  12. A limited spectrum of mutations causes constitutive activation of the yeast alpha-factor receptor.

    PubMed

    Sommers, C M; Martin, N P; Akal-Strader, A; Becker, J M; Naider, F; Dumont, M E

    2000-06-13

    Activation of G protein coupled receptors (GPCRs) by binding of ligand is the initial event in diverse cellular signaling pathways. To examine the frequency and diversity of mutations that cause constitutive activation of one particular GPCR, the yeast alpha-factor receptor, we screened libraries of random mutations for constitutive alleles. In initial screens for mutant receptor alleles that exhibit signaling in the absence of added ligand, 14 different point mutations were isolated. All of these 14 mutants could be further activated by alpha-factor. Ten of the mutants also acquired the ability to signal in response to binding of desTrp(1)¿Ala(3)ălpha-factor, a peptide that acts as an antagonist toward normal alpha-factor receptors. Of these 10 mutants, at least eight alleles residing in the third, fifth, sixth, and seventh transmembrane segments exhibit bona fide constitutive signaling. The remaining alleles are hypersensitive to alpha-factor rather than constitutive. They can be activated by low concentrations of endogenous alpha-factor present in MATa cells. The strongest constitutively active receptor alleles were recovered multiple times from the mutational libraries, and extensive mutagenesis of certain regions of the alpha-factor receptor did not lead to recovery of any additional constitutive alleles. Thus, only a limited number of mutations is capable of causing constitutive activation of this receptor. Constitutive and hypersensitive signaling by the mutant receptors is partially suppressed by coexpression of normal receptors, consistent with preferential association of the G protein with unactivated receptors. PMID:10841771

  13. Limiting prothrombin activation to meizothrombin is compatible with survival but significantly alters hemostasis in mice.

    PubMed

    Shaw, Maureen A; Kombrinck, Keith W; McElhinney, Kathryn E; Sweet, David R; Flick, Matthew J; Palumbo, Joseph S; Cheng, Mei; Esmon, Naomi L; Esmon, Charles T; Brill, Alexander; Wagner, Denisa D; Degen, Jay L; Mullins, Eric S

    2016-08-01

    Thrombin-mediated proteolysis is central to hemostatic function but also plays a prominent role in multiple disease processes. The proteolytic conversion of fII to α-thrombin (fIIa) by the prothrombinase complex occurs through 2 parallel pathways: (1) the inactive intermediate, prethrombin; or (2) the proteolytically active intermediate, meizothrombin (fIIa(MZ)). FIIa(MZ) has distinct catalytic properties relative to fIIa, including diminished fibrinogen cleavage and increased protein C activation. Thus, fII activation may differentially influence hemostasis and disease depending on the pathway of activation. To determine the in vivo physiologic and pathologic consequences of restricting thrombin generation to fIIa(MZ), mutations were introduced into the endogenous fII gene, resulting in expression of prothrombin carrying 3 amino acid substitutions (R157A, R268A, and K281A) to limit activation events to yield only fIIa(MZ) Homozygous fII(MZ) mice are viable, express fII levels comparable with fII(WT) mice, and have reproductive success. Although in vitro studies revealed delayed generation of fIIa(MZ) enzyme activity, platelet aggregation by fII(MZ) is similar to fII(WT) Consistent with prior analyses of human fIIa(MZ), significant prolongation of clotting times was observed for fII(MZ) plasma. Adult fII(MZ) animals displayed significantly compromised hemostasis in tail bleeding assays, but did not demonstrate overt bleeding. More notably, fII(MZ) mice had 2 significant phenotypic advantages over fII(WT) animals: protection from occlusive thrombosis after arterial injury and markedly diminished metastatic potential in a setting of experimental tumor metastasis to the lung. Thus, these novel animals will provide a valuable tool to assess the role of both fIIa and fIIa(MZ) in vivo. PMID:27252233

  14. Heterogeneity between triple negative breast cancer cells due to differential activation of Wnt and PI3K/AKT pathways.

    PubMed

    Martínez-Revollar, Gabriela; Garay, Erika; Martin-Tapia, Dolores; Nava, Porfirio; Huerta, Miriam; Lopez-Bayghen, Esther; Meraz-Cruz, Noemí; Segovia, José; González-Mariscal, Lorenza

    2015-11-15

    The lack of a successful treatment for triple-negative breast cancer demands the study of the heterogeneity of cells that constitute these tumors. With this aim, two clones from triple negative breast MDA-MB-231 cancer cells were isolated: One with fibroblast-like appearance (F) and another with semi-epithelial (SE) morphology. Cells of the F clone have a higher migration and tumorigenesis capacity than SE cells, suggesting that these cells are in a more advanced stage of epithelial to mesenchymal transformation. In agreement, F cells have a diminished expression of the tight junction proteins claudins 1 and 4, and an increased content of β-catenin. The latter is due to an augmented activity of the canonical Wnt route and of the EGFR/PI3K/mTORC2/AKT pathway favoring the cytoplasmic accumulation of β-catenin and its transcriptional activity. In addition, F cells display increased phosphorylation of β-catenin at Tyr654 by Src. These changes favor in F cells, the over-expression of Snail that promotes EMT. Finally, we observe that both F and SE cells display markers of cancer stem cells, which are more abundant in the F clone.

  15. Delayed glial clearance of degenerating axons in aged Drosophila is due to reduced PI3K/Draper activity.

    PubMed

    Purice, Maria D; Speese, Sean D; Logan, Mary A

    2016-01-01

    Advanced age is the greatest risk factor for neurodegenerative disorders, but the mechanisms that render the senescent brain vulnerable to disease are unclear. Glial immune responses provide neuroprotection in a variety of contexts. Thus, we explored how glial responses to neurodegeneration are altered with age. Here we show that glia-axon phagocytic interactions change dramatically in the aged Drosophila brain. Aged glia clear degenerating axons slowly due to low phosphoinositide-3-kinase (PI3K) signalling and, subsequently, reduced expression of the conserved phagocytic receptor Draper/MEGF10. Importantly, boosting PI3K/Draper activity in aged glia significantly reverses slow phagocytic responses. Moreover, several hours post axotomy, early hallmarks of Wallerian degeneration (WD) are delayed in aged flies. We propose that slow clearance of degenerating axons is mechanistically twofold, resulting from deferred initiation of axonal WD and reduced PI3K/Draper-dependent glial phagocytic function. Interventions that boost glial engulfment activity, however, can substantially reverse delayed clearance of damaged neuronal debris. PMID:27647497

  16. Delayed glial clearance of degenerating axons in aged Drosophila is due to reduced PI3K/Draper activity

    PubMed Central

    Purice, Maria D.; Speese, Sean D.; Logan, Mary A.

    2016-01-01

    Advanced age is the greatest risk factor for neurodegenerative disorders, but the mechanisms that render the senescent brain vulnerable to disease are unclear. Glial immune responses provide neuroprotection in a variety of contexts. Thus, we explored how glial responses to neurodegeneration are altered with age. Here we show that glia–axon phagocytic interactions change dramatically in the aged Drosophila brain. Aged glia clear degenerating axons slowly due to low phosphoinositide-3-kinase (PI3K) signalling and, subsequently, reduced expression of the conserved phagocytic receptor Draper/MEGF10. Importantly, boosting PI3K/Draper activity in aged glia significantly reverses slow phagocytic responses. Moreover, several hours post axotomy, early hallmarks of Wallerian degeneration (WD) are delayed in aged flies. We propose that slow clearance of degenerating axons is mechanistically twofold, resulting from deferred initiation of axonal WD and reduced PI3K/Draper-dependent glial phagocytic function. Interventions that boost glial engulfment activity, however, can substantially reverse delayed clearance of damaged neuronal debris. PMID:27647497

  17. Practical limitations of superresolution imaging due to conventional sample preparation revealed by a direct comparison of CLSM, SIM and dSTORM.

    PubMed

    Bachmann, Michael; Fiederling, Felix; Bastmeyer, Martin

    2016-06-01

    We evaluate the suitability of conventional sample preparation and labelling methods for two superresolution techniques, structured illumination microscopy and direct stochastic optical reconstruction microscopy, by a comparison to established confocal laser scanning microscopy. We show that SIM is compatible with standard fixation procedures and immunofluorescence labelling protocols and improves resolution by a factor of two compared to confocal laser scanning microscopy. With direct stochastic optical reconstruction microscopy, fluorophores can theoretically be localized with much higher precision. However, in practice, with indirect immunofluorescence labelling density can be insufficient due to the bulky probes to reveal biological structures with high resolution. Fine structures like single actin fibres are in fact resolved with direct stochastic optical reconstruction microscopy when using small affinity probes, but require proper adjustment of the fixation protocol. Finally, by a direct comparison of immunofluorescent and genetic labelling with fluorescent proteins, we show that target morphology in direct stochastic optical reconstruction microscopy data sets can differ significantly depending on the labelling method and the molecular environment of the target.

  18. A platform for actively loading cargo RNA to elucidate limiting steps in EV-mediated delivery.

    PubMed

    Hung, Michelle E; Leonard, Joshua N

    2016-01-01

    Extracellular vesicles (EVs) mediate intercellular communication through transfer of RNA and protein between cells. Thus, understanding how cargo molecules are loaded and delivered by EVs is of central importance for elucidating the biological roles of EVs and developing EV-based therapeutics. While some motifs modulating the loading of biomolecular cargo into EVs have been elucidated, the general rules governing cargo loading and delivery remain poorly understood. To investigate how general biophysical properties impact loading and delivery of RNA by EVs, we developed a platform for actively loading engineered cargo RNAs into EVs. In our system, the MS2 bacteriophage coat protein was fused to EV-associated proteins, and the cognate MS2 stem loop was engineered into cargo RNAs. Using this Targeted and Modular EV Loading (TAMEL) approach, we identified a configuration that substantially enhanced cargo RNA loading (up to 6-fold) into EVs. When applied to vesicles expressing the vesicular stomatitis virus glycoprotein (VSVG) - gesicles - we observed a 40-fold enrichment in cargo RNA loading. While active loading of mRNA-length (>1.5 kb) cargo molecules was possible, active loading was much more efficient for smaller (~0.5 kb) RNA molecules. We next leveraged the TAMEL platform to elucidate the limiting steps in EV-mediated delivery of mRNA and protein to prostate cancer cells, as a model system. Overall, most cargo was rapidly degraded in recipient cells, despite high EV-loading efficiencies and substantial EV uptake by recipient cells. While gesicles were efficiently internalized via a VSVG-mediated mechanism, most cargo molecules were rapidly degraded. Thus, in this model system, inefficient endosomal fusion or escape likely represents a limiting barrier to EV-mediated transfer. Altogether, the TAMEL platform enabled a comparative analysis elucidating a key opportunity for enhancing EV-mediated delivery to prostate cancer cells, and this technology should be of

  19. Ruthenium Dihydroxybipyridine Complexes are Tumor Activated Prodrugs Due to Low pH and Blue Light Induced Ligand Release

    PubMed Central

    Hufziger, Kyle T.; Thowfeik, Fathima Shazna; Charboneau, David J.; Nieto, Ismael; Dougherty, William G.; Kassel, W. Scott; Dudley, Timothy J.; Merino, Edward J.; Papish, Elizabeth T.; Paul, Jared J.

    2013-01-01

    Ruthenium drugs are potent anti-cancer agents, but inducing drug selectivity and enhancing their modest activity remain challenging. Slow Ru ligand loss limits the formation of free sites and subsequent binding to DNA base pairs. Herein, we designed a ligand that rapidly dissociates upon irradiation at low pH. Activation at low pH can lead to cancer selectivity, since many cancer cells have higher metabolism (and thus lower pH) than non-cancerous cells. We have used the pH sensitive ligand, 6,6′-dihydroxy-2,2′-bipyridine (66′bpy(OH)2), to generate [Ru(bpy)2(66′(bpy(OH)2)]2+, which contains two acidic hydroxyl groups with pKa1 = 5.26 and pKa2 = 7.27. Irradiation when protonated leads to photo-dissociation of the 66′bpy(OH)2 ligand. An in-depth study of the structural and electronic properties of the complex was carried out using X-Ray crystallography, electrochemistry, UV/visible spectroscopy, and computational techniques. Notably, Ru-N bond lengths in the 66′bpy(OH)2 complex are longer (by ~0.3 Å) than in polypyridyl complexes that lack 6 and 6′ substitution. Thus, the longer bond length predisposes the complex for photo-dissociation and leads to the anti-cancer activity. When the complex is deprotonated, the 66′bpy(O−)2 ligand molecular orbitals mix heavily with the ruthenium orbitals, making new mixed metal-ligand orbitals that lead to a higher bond order. We investigated the anti-cancer activities of [Ru(bpy)2(66′(bpy(OH)2)]2+, [Ru(bpy)2(44′(bpy(OH)2)]2+, and [Ru(bpy)3]2+ (44′(bpy(OH)2 = 4,4′-dihydroxy-2,2′-bipyridine) in HeLa cells, which have a relatively low pH. It is found that [Ru(bpy)2(66′(bpy(OH)2)]2+ is more cytotoxic than the other ruthenium complexes studied. Thus, we have identified a pH sensitive ruthenium scaffold that can be exploited for photo-induced anti-cancer activity. PMID:24184694

  20. Impact of reduced dose limits on NRC licensed activities. Major issues in the implementation of ICRP/NCRP dose limit recommendations: Final report

    SciTech Connect

    Meinhold, C.B.

    1995-05-01

    This report summarizes information required to estimate, at least qualitatively, the potential impacts of reducing occupational dose limits below those given in 10 CFR 20 (Revised). For this study, a questionnaire was developed and widely distributed to the radiation protection community. The resulting data together with data from existing surveys and sources were used to estimate the impact of three dose-limit options; 10 mSv yr{sup {minus}1} (1 rem yr{sup {minus}1}), 20 mSv yr{sup {minus}1} (2 rem yr{sup {minus}1}), and a combination of an annual limit of 50 mSv yr{sup {minus}1} (5 rem yr{sup {minus}1}) coupled with a cumulative limit, in rem, equal to age in years. Due to the somewhat small number of responses and the lack of data in some specific areas, a working committee of radiation protection experts from a variety of licensees was employed to ensure the exposure data were representative. The following overall conclusions were reached: (1) although 10 mSv yr{sup {minus}1} is a reasonable limit for many licensees, such a limit could be extraordinarily difficult to achieve and potentially destructive to the continued operation of some licensees, such as nuclear power, fuel fabrication, and medicine; (2) twenty mSv yr{sup {minus}1} as a limit is possible for some of these groups, but for others it would prove difficult. (3) fifty mSv yr{sup {minus}1} and age in 10s of mSv appear reasonable for all licensees, both in terms of the lifetime risk of cancer and severe genetic effects to the most highly exposed workers, and the practicality of operation.

  1. Target sequence accessibility limits activation-induced cytidine deaminase activity in primary mediastinal B-cell lymphoma.

    PubMed

    Popov, Sergey W; Moldenhauer, Gerhard; Wotschke, Beate; Brüderlein, Silke; Barth, Thomas F; Dorsch, Karola; Ritz, Olga; Möller, Peter; Leithäuser, Frank

    2007-07-15

    Activation-induced cytidine deaminase (AID) initiates somatic hypermutation (SHM) and class switch recombination (CSR) in activated B lymphocytes and is potentially implicated in genomic instability of B-cell malignancies. For unknown reasons, B-cell neoplasms often lack SHM and CSR in spite of high AID expression. Here, we show that primary mediastinal B-cell lymphoma (PMBL), an immunoglobulin (Ig)-negative lymphoma that possesses hypermutated, class-switched Ig genes, expresses high levels of AID with an intact primary structure but does not do CSR in 14 of 16 cases analyzed. Absence of CSR coincided with low Ig germ-line transcription, whereas high level germ-line transcription was observed only in those two cases with active CSR. Interleukin-4/CD40L costimulation induced CSR and a marked up-regulation of germ-line transcription in the PMBL-derived cell line MedB-1. In the PMBL cell line Karpas 1106P, CSR was not inducible and germ-line transcription remained low on stimulation. However, Karpas 1106P, but not MedB-1, had ongoing SHM of the Ig gene and BCL6. These genes were transcribed in Karpas 1106P, whereas transcription was undetectable or low in MedB-1 cells. Thus, accessibility of the target sequences seems to be a major limiting factor for AID-dependent somatic gene diversification in PMBL. PMID:17638864

  2. Are Functional and Activity Limitations Becoming More Prevalent among 55 to 69-Year-Olds in the United States?

    PubMed Central

    Choi, HwaJung; Schoeni, Robert F.; Martin, Linda G.

    2016-01-01

    Objectives This study examines changes in functional and activity limitations 1998–2012 for individuals 55–69. Methods Logistic models are used to estimate trends in limitations in vision, hearing, physical and cognitive functioning, IADLs, and ADLs. Additional models assess the extent to which trends are associated with and differ by education, smoking, and BMI. Results Changes in prevalence of limitations in vision, hearing, cognitive functioning, and ADLs are not statistically significant. Limitations in physical functioning declined by 0.37% per year. IADL limitations increased by 1.33% per year, but most of the increase occurred between 2008 and 2010/2012, and are associated with economic hardship during the Great Recession. Increases in education are especially beneficially associated with trends in limitations, but reductions in smoking also appear to be advantageous for some outcomes. Increases in BMI are associated with trends in physical functioning, IADL, and ADL limitation. Discussion For Americans 55–69, functional and activity limitations were largely unchanged 1998–2012. Our results suggest that if educational attainment had not increased, most functional and activity limitations potentially could have worsened substantially. Future change in educational attainment is not expected to be so positive. Continued monitoring of trends in activity limitations might well include greater focus on the explanatory roles of environmental factors, including economic circumstances. PMID:27783638

  3. A Chromogenic Assay Suitable for High-Throughput Determination of Limit Dextrinase Activity in Barley Malt Extracts.

    PubMed

    Bøjstrup, Marie; Marri, Lucia; Lok, Finn; Hindsgaul, Ole

    2015-12-23

    Twenty-four malt samples were assayed for limit dextrinase activity using a chromogenic assay developed recently in our group. The assay utilizes a small soluble chromogenic substrate which is hydrolyzed selectively by limit dextrinase in a coupled assay to release the chromophore 2-chloro-4-nitrophenol. The release of the chromophore, corresponding to the activity of limit dextrinase, can be followed by measuring the UV absorption at 405 nm. The 24 malt samples represented a wide variation of limit dextrinase activities, and these activities could be clearly differentiated by the assay. The results obtained were comparable with the results obtained from a commercially available assay, Limit-Dextrizyme from Megazyme International Ireland. Furthermore, the improved assay uses a soluble substrate. That makes it well suited for high-throughput screening as it can be handled in a 96-well plate format. PMID:26615836

  4. Quantitative analysis of tumor shrinkage due to chemotherapy and its implication for radiation treatment planning in limited-stage small-cell lung cancer

    PubMed Central

    2013-01-01

    Background The optimal timing of chemoradiotherapy in limited-stage small-cell lung cancer (LS-SCLC) hasn’t been established, although evidence from studies supported that patients can benefit from early radiation therapy. The purpose of this study was to quantify tumor shrinkage in response to induction chemotherapy (IC), evaluate the impact of tumor shrinkage on radiation dosimetric parameters and determine its implication for the timing of radiation therapy for patients with LS-SCLC. Methods Twenty patients with LS-SCLC who were treated with IC followed by concomitant radiation therapy were investigated retrospectively. Ten patients received 1 cycle of IC, and 10 patients received 2 cycles of IC. Pre-IC CT imaging was coregistered with a simulation CT, and virtual radiation plans were created for pre- and post-IC thoracic disease in each case. The changes in the gross target volume (GTV), planning target volume (PTV) and dosimetric factors associated with the lungs, esophagus and heart were analyzed. Results The mean GTV and PTV for all of the patients decreased by 60.9% and 40.2%, respectively, which resulted in a significant reduction in the radiation exposure to the lungs, esophagus and heart. Changes in the PTV and radiation exposure of normal tissue were not significantly affected by the number of chemotherapy cycles delivered, although patients who received 2 cycles of IC had a greater decrease in GTV than those who received only 1 cycle of IC (69.6% vs. 52.1%, p = 0.273). Conclusions Our data showed that targeting the tumor post-IC may reduce the radiation dose to normal tissue in patients with LS-SCLC. However, the benefit to the normal tissue was not increased by an additional cycle of IC. These findings suggest that the first cycle of chemotherapy is very important for tumor shrinkage and that initiating thoracic radiation therapy at the second cycle of chemotherapy may be a reasonable strategy for timing of radiation therapy in LS

  5. Ethanolic extracts of Alstonia Scholaris and Bacopa Monniera possess neuroleptic activity due to anti-dopaminergic effect

    PubMed Central

    Jash, Rajiv; Chowdary, K. Appana

    2014-01-01

    Background: An increased inclination has been observed for the use of herbal drugs in chronic and incurable diseases. Treatment of psychiatric diseases like schizophrenia is largely palliative and more importantly, a prominent adverse effect prevails with the majority of anti-psychotic drugs, which are the extrapyramidal motor disorders. Existing anti-psychotic drug therapy is not so promising, and their adverse effect is a matter of concern for continuing the therapy for long duration. Objective: This experimental study was done to evaluate the neuroleptic activity of the ethanolic extracts of two plants Alstonia Scholaris and Bacopa Monnieri with different anti-psychotic animal models with a view that these plant extracts shall have no or at least reduced adverse effect so that it can be used for long duration. Materials and Methods: Two doses of both the extracts (100 and 200 mg/kg) and also standard drug haloperidol (0.2 mg/kg) were administered to their respective groups once daily with 5 different animal models. After that, the concentration of the dopamine neurotransmitter was estimated in two different regions of the brain viz. frontal cortex and striatum. Results: The result of the study indicated a significant reduction of amphetamine-induced stereotype and conditioned avoidance response for both the extracts compared with the control group, but both did not have any significant effect in phencyclidine-induced locomotor activity and social interaction activity. However, both the extracts showed minor signs of catalepsy compared to the control group. The study also revealed that the neuroleptic effect was due to the reduction of the dopamine concentration in the frontal cortex region of the rat brain. The results largely pointed out the fact that both the extract may be having the property to alleviate the positive symptoms of schizophrenia by reducing the dopamine levels of dopaminergic neurons of the brain. Conclusion: The estimation of dopamine in the

  6. Active Interrogation Observables for Enrichment Determination of DU Shielded HEU Metal Assemblies with Limited Geometrical Information

    SciTech Connect

    Pena, Kirsten E; McConchie, Seth M; Crye, Jason Michael; Mihalczo, John T

    2011-01-01

    Determining the enrichment of highly enriched uranium (HEU) metal assemblies shielded by depleted uranium (DU) proves a unique challenge to currently employed measurement techniques. Efforts to match time-correlated neutron distributions obtained through active interrogation to Monte Carlo simulations of the assemblies have shown promising results, given that the exact geometries of both the HEU metal assemblies and DU shields are known from imaging and fission site mapping. In certain situations, however, it is desirable to obtain enrichment with limited or no geometrical information of the assemblies being measured. This paper explores the possibility that the utilization of observables in the interrogation of assemblies by time-tagged D-T neutrons, including time-correlated distribution of neutrons and gammas using liquid scintillators operating on the fission chain time scale, can lead to enrichment determination without a complete set of geometrical information.

  7. Application of active quenching of second generation wire for current limiting

    DOE PAGES

    Solovyov, Vyacheslav F.; Li, Qiang

    2015-10-19

    Superconducting fault current limiters (SFCL's) are increasingly implemented in the power grid as a protection of substation equipment from fault currents. Resistive SFCL's are compact and light, however they are passively triggered and thus may not be sufficiently sensitive to respond to faults in the distribution grid. Here, we explore the prospect of adding an active management feature to a traditional resistive SFCL. A flexible radio-frequency coil, which is an integral part of the switching structure, acts as a triggering device. We show that the application of a short, 10 ms, burst of ac magnetic field during the fault triggersmore » a uniform quench of the wire and significantly reduces the reaction time of the wire at low currents. The ac field burst generates a high density of normal zones, which merge into a continuous resistive region at a rate much faster than that of sparse normal zones created by the transport current alone.« less

  8. Application of active quenching of second generation wire for current limiting

    SciTech Connect

    Solovyov, Vyacheslav F.; Li, Qiang

    2015-10-19

    Superconducting fault current limiters (SFCL's) are increasingly implemented in the power grid as a protection of substation equipment from fault currents. Resistive SFCL's are compact and light, however they are passively triggered and thus may not be sufficiently sensitive to respond to faults in the distribution grid. Here, we explore the prospect of adding an active management feature to a traditional resistive SFCL. A flexible radio-frequency coil, which is an integral part of the switching structure, acts as a triggering device. We show that the application of a short, 10 ms, burst of ac magnetic field during the fault triggers a uniform quench of the wire and significantly reduces the reaction time of the wire at low currents. The ac field burst generates a high density of normal zones, which merge into a continuous resistive region at a rate much faster than that of sparse normal zones created by the transport current alone.

  9. Activation Barrier-Limited Folding and Conformational Sampling of a Dynamic Protein Domain.

    PubMed

    Dogan, Jakob; Toto, Angelo; Andersson, Eva; Gianni, Stefano; Jemth, Per

    2016-09-20

    Folding reaction mechanisms of globular protein domains have been extensively studied by both experiment and simulation and found to be highly concerted chemical reactions in which numerous noncovalent bonds form in an apparent two-state fashion. However, less is known regarding intrinsically disordered proteins because their folding can usually be studied only in conjunction with binding to a ligand. We have investigated by kinetics the folding mechanism of such a disordered protein domain, the nuclear coactivator-binding domain (NCBD) from CREB-binding protein. While a previous computational study suggested that NCBD folds without an activation free energy barrier, our experimental data demonstrate that NCBD, despite its highly dynamic structure, displays relatively slow folding (∼10 ms at 277 K) consistent with a barrier-limited process. Furthermore, the folding kinetics corroborate previous nuclear magnetic resonance data showing that NCBD exists in two folded conformations and one more denatured conformation at equilibrium and, thus, that the folding mechanism is a three-state mechanism. The refolding kinetics is limited by unfolding of the less populated folded conformation, suggesting that the major route for interconversion between the two folded states is via the denatured state. Because the two folded conformations have been suggested to bind distinct ligands, our results have mechanistic implications for conformational sampling in protein-protein interactions. PMID:27542287

  10. The Luminosity Function of Quasars (active Galactic Nuclei) in a Merging Model with the Eddington Limit Taken Into Account

    NASA Astrophysics Data System (ADS)

    Kontorovich, V. M.; Krivitsky, D. S.

    The influence of Eddington's limit on the active galactic nuclei (AGN) luminosity function within the framework of a phenomenological activity model (Kats and Kontorovich, 1990, 1991) based on angular momentum compensation in the process of galaxy merging is investigated. In particular, it is shown that in spite of the essential dependence of the galaxy merging probability on their masses in the most important and interesting case it behaves effectively as a constant, so that the abovementioned (Kats and Kontorovich, 1991) correspondence between the observed galaxy mass function (Binggeli et al., 1988) and quasar luminosity function power exponents (Boyle et al., 1988; Koo and Kron, 1988; Cristiani et al., 1993) for a constant merger probability takes place in reality. A break in the power-law dependence of the luminosity function due to Eddington's restriction (cf. Dibai, 1981; Padovani and Rafanelli, 1988) is obtained in certain cases. Possible correlation between masses of black holes in AGN and masses of their host galaxies is discussed. A more detailed paper containing the results presented at this conference was published in Pis'ma v Astron. Zh. (Kontorovich and Krivitsky, 1995). Here we have added also some additional notes and references.

  11. Rapid community identification, pain and distress associated with lymphoedema and adenolymphangitis due to lymphatic filariasis in resource-limited communities of North-eastern Nigeria.

    PubMed

    Akogun, O B; Akogun, M K; Apake, E; Kale, O O

    2011-09-01

    Identification of communities with people that could benefit from adenolymphangitis (ADL) and lymphoedema morbidity management within Lymphatic Filariasis Elimination Programmes (NLFEP) in many African countries is a major challenge to programme managers. Another challenge is advocating for proportionate allocation of funds to alleviating the suffering that afflicted people bear. In this study we developed a rapid qualitative technique of identifying communities where morbidity management programme could be situated and documenting the pain and distress that afflicted persons endure. Estimates given by health personnel and by community resource persons were compared with systematic household surveys for the number of persons with lymphoedema of the lower limb. Communities in Northeastern Nigeria, with the largest number of lymphoedema cases were selected and a study of local knowledge, physical, psychosocial burden and intervention-seeking activities associated with the disease documented using an array of techniques (including household surveys, key informant interviews, group discussions and informal conversations). Health personnel gave a more accurate estimate of the number of lymphoedema patients in their communities than either the community leader or the community directed ivermectin distributor (CDD). Community members with lymphoedema preferred to confide in health personnel from other communities. The people had a well developed local vocabulary for lymphoedema and are well aware of the indigenous transmission theories. Although the people associated the episodic ADL attacks with the rains which were more frequent at that period they did not associate the episodes with gross lymphoedema. There were diverse theories about lymphoedema causation with heredity, accidental stepping on charmed objects and organisms, breaking taboos. The most popular belief about causation, however, is witchcraft (60.9%). The episodic attacks are dreaded by the afflicted, since

  12. Prevalence of complex activity limitations among racial/ethnic groups and Hispanic subgroups of adults: United States, 2003-2009.

    PubMed

    Ward, Brian W; Schiller, Jeannine S

    2011-09-01

    This brief has shown that racial and ethnic differences exist in the prevalence of complex activity limitations among adults. Further, within the U.S. Hispanic adult population, a number of significant differences were found in complex activity limitations among Mexican, Puerto Rican, Cuban, Central or South American, and other Hispanic adults—differences that would likely go unnoticed if the Hispanic population were treated as a single group. These disparities in the prevalence of complex activity limitations are further influenced by sex and age.

  13. 26 CFR 1.103(n)-1T - Limitation on aggregrate amount of private activity bonds (temporary).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... activity bonds (temporary). 1.103(n)-1T Section 1.103(n)-1T Internal Revenue INTERNAL REVENUE SERVICE... Excluded from Gross Income § 1.103(n)-1T Limitation on aggregrate amount of private activity bonds (temporary). Q-1: What does section 103(n) provide? A-1: Interest on an issue of private activity bonds...

  14. 26 CFR 1.103(n)-1T - Limitation on aggregrate amount of private activity bonds (temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... activity bonds (temporary). 1.103(n)-1T Section 1.103(n)-1T Internal Revenue INTERNAL REVENUE SERVICE... Excluded from Gross Income § 1.103(n)-1T Limitation on aggregrate amount of private activity bonds (temporary). Q-1: What does section 103(n) provide? A-1: Interest on an issue of private activity bonds...

  15. Active load path adaption in a simple kinematic load-bearing structure due to stiffness change in the structure's supports

    NASA Astrophysics Data System (ADS)

    Gehb, C. M.; Platz, R.; Melz, T.

    2016-09-01

    Load-bearing structures with kinematic functions enable and disable degrees of freedom and are part of many mechanical engineering applications. The relative movement between a wheel and the body of a car or a landing gear and an aircraft fuselage are examples for load-bearing systems with defined kinematics. In most cases, the load is transmitted through a predetermined load path to the structural support interfaces. However, unexpected load peaks or varying health condition of the system's supports, which means for example varying damping and stiffness characteristics, may require an active adjustment of the load path. However, load paths transmitted through damaged or weakened supports can be the reason for reduced comfort or even failure. In this paper a simplified 2D two mass oscillator with two supports is used to numerically investigate the potential of controlled adaptive auxiliary kinematic guidance elements in a load-bearing structure to adapt the load path depending on the stiffness change, representing damage of the supports. The aim is to provide additional forces in the auxiliary kinematic guidance elements for two reasons. On the one hand, one of the two supports that may become weaker through stiffness change will be relieved from higher loading. On the other hand, tilting due to different compliance in the supports will be minimized. Therefore, shifting load between the supports during operation could be an effective option.

  16. Testing the limits of rational design by engineering pH sensitivity into membrane active peptides

    PubMed Central

    Wiedman, Gregory

    2015-01-01

    In this work, we sought to rationally design membrane active peptides that are triggered by low pH to form macromolecular-sized pores in lipid bilayers. Such peptides could have broad utility in biotechnology and in nanomedicine as cancer therapeutics or drug delivery vehicles that promote release of macromolecules from endosomes. Our approach to rational design was to combine the properties of a pH-independent peptide, MelP5, which forms large pores allowing passage of macromolecules, with the properties of two pH-dependent membrane active peptides, pHlip and GALA. We created two hybrid sequences, MelP5_Δ4 and MelP5_Δ6 by using the distribution of acidic residues on pHlip and GALA as a guide to insert acidic amino acids into the amphipathic helix of MelP5. We show that the new peptides bind to lipid bilayers and acquire secondary structure in a pH-dependent manner. The peptides also destabilize bilayers in a pH-dependent manner, such that lipid vesicles release the small molecules ANTS/DPX at low pH only. Thus, we were successful in designing pH-triggered pore-forming peptides. However, no macro-molecular release was observed under any conditions. Therefore, we abolished the unique macromolecular poration properties of MelP5 by introducing pH-sensitivity into its sequence. We conclude that the properties of pHlip, GALA and MelP5 are additive, but only partially so. We propose that this lack of additivity is a limitation in the rational design of novel membrane active peptides, and that high-throughput approaches to discovery will be critical for continued progress in the field. PMID:25572997

  17. Utilizing an Extraterrestrial Analogue to Predict Sediment Migration on Frenchman Flat due to Convective Vortex (Dust Devil) Activity

    NASA Astrophysics Data System (ADS)

    McGee, B. W.

    2006-12-01

    data from the NTS, and combining them with measurements of sediment loading and erosive strength in terrestrial dust devils, it is possible to both illustrate the potential significance of dust devils to currently-accepted radionuclide residence time on Frenchman Flat playa, as well as predict areas of unexpected radionuclide migration and/or attenuation due to dust devil activity.

  18. 26 CFR 1.103(n)-4T - Elective carryforward of unused private activity bond limit (temporary).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... bond limit (temporary). 1.103(n)-4T Section 1.103(n)-4T Internal Revenue INTERNAL REVENUE SERVICE... Excluded from Gross Income § 1.103(n)-4T Elective carryforward of unused private activity bond limit... carryforward for any one or more projects described in A-5 of this § 1.103(n)-4T (carryforward projects)....

  19. 26 CFR 1.103(n)-4T - Elective carryforward of unused private activity bond limit (temporary).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... bond limit (temporary). 1.103(n)-4T Section 1.103(n)-4T Internal Revenue INTERNAL REVENUE SERVICE... Excluded from Gross Income § 1.103(n)-4T Elective carryforward of unused private activity bond limit... carryforward for any one or more projects described in A-5 of this § 1.103(n)-4T (carryforward projects)....

  20. Activity limitations and participation restrictions in women with hand osteoarthritis: patients' descriptions and associations between dimensions of functioning

    PubMed Central

    Kjeken, I; Dagfinrud, H; Slatkowsky-Christ..., B; Mowinckel, P; Uhlig, T; Kvien, T; Finset, A

    2005-01-01

    Objective: To describe the functional consequences of hand osteoarthritis, and analyse associations between personal factors, hand impairment, activity limitations, and participation restrictions within the framework of the International Classification of Functioning (ICF). Methods: 87 women with hand osteoarthritis completed a clinical examination including recording of sociodemographic data, measures of hand impairment, and completion of self reported health status measures. The function subscale of the AUSCAN Osteoarthritis Hand Index was used as a measure of hand related activity limitations, while the Canadian Occupational Performance Measure (COPM) was used to describe and measure activity limitations and participation restrictions as perceived by the individual. The study variables were categorised using the dimensions in the ICF framework and analysed using bivariate and multivariate statistical approaches. Results: The patients described problems in many domains of activity and participation. The most frequently described hand related problems were activities requiring considerable grip strength combined with twisting of the hands. On the impairment level, the patients had reduced grip force and joint mobility in the hands, and resisted motion was painful. Regression analyses showed that hand related activity limitations were associated with measures of hand impairment, while activity and participation (as measured by the COPM) were more strongly associated with personal factors than with hand impairment. Conclusions: Hand osteoarthritis has important functional consequences in terms of pain, reduced hand mobility and grip force, activity limitations, and participation restrictions. Rehabilitation programmes should therefore be multidisciplinary and multidimensional, focusing on hand function, occupational performance, and coping strategies. PMID:15829571

  1. Floral resource limitation severely reduces butterfly survival, condition and flight activity in simplified agricultural landscapes.

    PubMed

    Lebeau, Julie; Wesselingh, Renate A; Van Dyck, Hans

    2016-02-01

    Agricultural intensification has a strong negative impact on farmland biodiversity (including flower-visiting insects), but understanding the mechanisms involved in this requires experimental work. We document the impact of nectar limitation on the performance of a flower-visiting insect, the meadow brown butterfly Maniola jurtina. We conducted two types of experiments: a field experiment in agricultural landscapes with grasslands of different management intensity and an experiment in outdoor flight cages in which the nectar supply was simulated. For the field experiment, we introduced an array of nectar resources in intensively managed, nectar-poor meadows and in extensively managed, flower-rich grasslands and counted flower visitors. Despite higher butterfly abundance in the extensive meadows, our introduced nectar sources were more frequently visited in intensive meadows, indicating the lack of floral resources. The 48-h confinement under nectar-poor conditions in the flight cages had a strong negative effect on body condition, flight activity and lifetime survival compared to butterflies under nectar-rich conditions. Female lifespan was reduced by 22% and male lifespan even by 43%. Agricultural landscapes that provide limited amounts of floral nectar, and no high-quality, preferred nectar sources relative to the needs of the flower-visiting species, may create ecological sinks. Regards an insect's performance, the simple presence of nectar is not necessarily functionally adequate. The effectiveness of agri-environmental schemes for flower-visiting insects (e.g. flower strips) could be improved based on ecological and evolutionary insights on the effects of specific nectar quantities and qualities.

  2. Morphodynamics of Travertine Dam/Waterfall Growth due to the Interaction of Biological Activity, Water Flow and Limestone Emplacement

    NASA Astrophysics Data System (ADS)

    Izumi, N.; Parker, G.

    2012-12-01

    Plitvice Lakes in Croatia are characterized by a step-like train of lakes and waterfalls. The waterfalls are located at the crests of naturally-emplaced dams. The top of each dam grows upward at the rate of a few millimeters per year. It is thought that the upward growth of these dams is caused by the interaction of water flow and biological activity, resulting in the precipitation of dissolved limestone. Dam evolution is initiated by the growth of mosses that favor swift, shallow water. Bacteria that inhabit the roots of the moss excrete solid limestone (travertine) from the water. The limestone fossilizes the moss, and then more moss grows on top of the travertine deposit. In this way, the natural dam can grow over to 10 m high, impounding the water behind it to form a lake. We propose a simple model to explain the formation of natural limestone dams by the interaction between water flow and biologically-mediated travertine deposition. We assume for simplicity that light is the only factor determining the growth of moss, which is then colonized by travertine-emplacing bacteria. We also assume that the water is saturated with dissolved limestone, so that the process is not limited by limestone availability. Photosynthesis, and thus the growth rate of moss are crudely approximated as decreasing linearly with depth. We employ the shallow water equations to describe water flow over the dam. In order to obtain a profile of permanent form for a dam migrating upward and downstream at constant speed, we solve the problem in a moving coordinate system. When water flows over the dam, it is accelerated in the streamwise direction, and the water surface forms a backwater curve. The flow regime changes from Froude-subcritical to Froude-supercritical at a point slightly downstream of the crest of the dam. Farther downstream, the flow attains a threshold velocity beyond which moss is detached. This threshold point defines the downstream end of the active part of the dam. The

  3. The Miscoding Potential of 5-Hydroxycytosine Arises Due to Template Instability in the Replicative Polymerase Active Site

    SciTech Connect

    Zahn, Karl E.; Averill, April; Wallace, Susan S.; Doublié, Sylvie

    2012-07-18

    5-Hydroxycytosine (5-OHC) is a stable oxidation product of cytosine associated with an increased frequency of C {yields} T transition mutations. When this lesion escapes recognition by the base excision repair pathway and persists to serve as a templating base during DNA synthesis, replicative DNA polymerases often misincorporate dAMP at the primer terminus, which can lead to fixation of mutations and subsequent disease. To characterize the dynamics of DNA synthesis opposite 5-OHC, we initiated a comparison of unmodified dCMP to 5-OHC, 5-fluorocytosine (5-FC), and 5-methylcytosine (5-MEC) in which these bases act as templates in the active site of RB69 gp43, a high-fidelity DNA polymerase sharing homology with human replicative DNA polymerases. This study presents the first crystal structure of any DNA polymerase binding this physiologically important premutagenic DNA lesion, showing that while dGMP is stabilized by 5-OHC through normal Watson-Crick base pairing, incorporation of dAMP leads to unstacking and instability in the template. Furthermore, the electronegativity of the C5 substituent appears to be important in the miscoding potential of these cytosine-like templates. While dAMP is incorporated opposite 5-OHC {approx}5 times more efficiently than opposite unmodified dCMP, an elevated level of incorporation is also observed opposite 5-FC but not 5-MEC. Taken together, these data imply that the nonuniform templating by 5-OHC is due to weakened stacking capabilities, which allows dAMP incorporation to proceed in a manner similar to that observed opposite abasic sites.

  4. Association of Objectively Measured Physical Activity With Cardiovascular Risk in Mobility‐limited Older Adults

    PubMed Central

    Fitzgerald, Jodi D.; Johnson, Lindsey; Hire, Don G.; Ambrosius, Walter T.; Anton, Stephen D.; Dodson, John A.; Marsh, Anthony P.; McDermott, Mary M.; Nocera, Joe R.; Tudor‐Locke, Catrine; White, Daniel K.; Yank, Veronica; Pahor, Marco; Manini, Todd M.; Buford, Thomas W.

    2015-01-01

    Background Data are sparse regarding the impacts of habitual physical activity (PA) and sedentary behavior on cardiovascular (CV) risk in older adults with mobility limitations. Methods and Results This study examined the baseline, cross‐sectional association between CV risk and objectively measured PA among participants in the Lifestyle Interventions and Independence for Elders (LIFE) study. The relationship between accelerometry measures and predicted 10‐year Hard Coronary Heart Disease (HCHD) risk was modeled by using linear regression, stratified according to CVD history. Participants (n=1170, 79±5 years) spent 642±111 min/day in sedentary behavior (ie, <100 accelerometry counts/min). They also spent 138±43 min/day engaging in PA registering 100 to 499 accelerometry counts/min and 54±37 min/day engaging in PA ≥500 counts/min. Each minute per day spent being sedentary was associated with increased HCHD risk among both those with (0.04%, 95% CI 0.02% to 0.05%) and those without (0.03%, 95% CI 0.02% to 0.03%) CVD. The time spent engaging in activities 100 to 499 as well as ≥500 counts/min was associated with decreased risk among both those with and without CVD (P<0.05). The mean number of counts per minute of daily PA was not significantly associated with HCHD risk in any model (P>0.05). However, a significant interaction was observed between sex and count frequency (P=0.036) for those without CVD, as counts per minute was related to HCHD risk in women (β=−0.94, −1.48 to −0.41; P<0.001) but not in men (β=−0.14, −0.59 to 0.88; P=0.704). Conclusions Daily time spent being sedentary is positively associated with predicted 10‐year HCHD risk among mobility‐limited older adults. Duration, but not intensity (ie, mean counts/min), of daily PA is inversely associated with HCHD risk score in this population—although the association for intensity may be sex specific among persons without CVD. Clinical Trial Registration URL: www

  5. Renal sodium retention in cirrhotic rats depends on glucocorticoid-mediated activation of mineralocorticoid receptor due to decreased renal 11beta-HSD-2 activity.

    PubMed

    Thiesson, Helle C; Jensen, Boye L; Bistrup, Claus; Ottosen, Peter D; McNeilly, Alison D; Andrew, Ruth; Seckl, Jonathan; Skøtt, Ole

    2007-01-01

    Downregulation of the renal glucocorticoid-metabolizing enzyme 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD-2) during liver cirrhosis may allow activation of the mineralocorticoid receptor (MR) by glucocorticoids and contribute to sodium retention. We tested this hypothesis in male Wistar rats with decompensated liver cirrhosis and ascites 7 wk after bile duct ligation (BDL). Renal 11beta-HSD-2 mRNA, protein, and activity were significantly decreased in decompensated rats. The urinary Na(+)/K(+) ratio was reduced by 40%. Renal epithelial sodium channel (ENaC) mRNA and immunostaining were only slightly affected. Complete metabolic studies, including fecal excretion, showed that the BDL rats had avid renal sodium retention. Treatment of the BDL rats with dexamethasone suppressed endogenous glucocorticoid production, normalized total sodium balance and renal sodium excretion, and reduced ascites formation to the same degree as direct inhibition of MR with K-canrenoate. Total potassium balance was negative in the BDL rats, whereas renal potassium excretion was unchanged. In the distal colon, expression of ENaC was increased in BDL rats. Fecal potassium excretion was increased in cirrhotic rats, and this was corrected by treatment with K-canrenoate but not dexamethasone. We conclude that development of sodium retention and decompensation in cirrhotic rats is associated with downregulation of renal 11beta-HSD-2 activity and inappropriate activation of renal sodium reabsorption by endogenous glucocorticoids. In addition, the overall potassium loss in the BDL model is due to increased fecal potassium excretion, which is associated with upregulation of ENaC in distal colon. PMID:16917017

  6. High molecular weight hyaluronic acid limits astrocyte activation and scar formation after spinal cord injury

    NASA Astrophysics Data System (ADS)

    Khaing, Zin Z.; Milman, Brian D.; Vanscoy, Jennifer E.; Seidlits, Stephanie K.; Grill, Raymond J.; Schmidt, Christine E.

    2011-08-01

    A major hurdle for regeneration after spinal cord injury (SCI) is the ability of axons to penetrate and grow through the scar tissue. After SCI, inflammatory cells, astrocytes and meningeal cells all play a role in developing the glial scar. In addition, degradation of native high molecular weight (MW) hyaluronic acid (HA), a component of the extracellular matrix, has been shown to induce activation and proliferation of astrocytes. However, it is not known if the degradation of native HA actually enhances glial scar formation. We hypothesize that the presence of high MW HA (HA with limited degradation) after SCI will decrease glial scarring. Here, we demonstrate that high MW HA decreases cell proliferation and reduces chondroitin sulfate proteoglycan (CSPG) production in cultured neonatal and adult astrocytes. In addition, stiffness-matched high MW HA hydrogels crosslinked to resist degradation were implanted in a rat model of spinal dorsal hemisection injury. The numbers of immune cells (macrophages and microglia) detected at the lesion site in animals with HA hydrogel implants were significantly reduced at acute time points (one, three and ten days post-injury). Lesioned animals with HA implants also exhibited significantly lower CSPG expression at ten days post-injury. At nine weeks post-injury, animals with HA hydrogel implants exhibited a significantly decreased astrocytic response, but did not have significantly altered CSPG expression. Combined, these data suggest that high MW HA, when stabilized against degradation, mitigates astrocyte activation in vitro and in vivo. The presence of HA implants was also associated with a significant decrease in CSPG deposition at ten days after SCI. Therefore, HA-based hydrogel systems hold great potential for minimizing undesired scarring as part of future repair strategies after SCI.

  7. High molecular weight hyaluronic acid limits astrocyte activation and scar formation after spinal cord injury.

    PubMed

    Khaing, Zin Z; Milman, Brian D; Vanscoy, Jennifer E; Seidlits, Stephanie K; Grill, Raymond J; Schmidt, Christine E

    2011-08-01

    A major hurdle for regeneration after spinal cord injury (SCI) is the ability of axons to penetrate and grow through the scar tissue. After SCI, inflammatory cells, astrocytes and meningeal cells all play a role in developing the glial scar. In addition, degradation of native high molecular weight (MW) hyaluronic acid (HA), a component of the extracellular matrix, has been shown to induce activation and proliferation of astrocytes. However, it is not known if the degradation of native HA actually enhances glial scar formation. We hypothesize that the presence of high MW HA (HA with limited degradation) after SCI will decrease glial scarring. Here, we demonstrate that high MW HA decreases cell proliferation and reduces chondroitin sulfate proteoglycan (CSPG) production in cultured neonatal and adult astrocytes. In addition, stiffness-matched high MW HA hydrogels crosslinked to resist degradation were implanted in a rat model of spinal dorsal hemisection injury. The numbers of immune cells (macrophages and microglia) detected at the lesion site in animals with HA hydrogel implants were significantly reduced at acute time points (one, three and ten days post-injury). Lesioned animals with HA implants also exhibited significantly lower CSPG expression at ten days post-injury. At nine weeks post-injury, animals with HA hydrogel implants exhibited a significantly decreased astrocytic response, but did not have significantly altered CSPG expression. Combined, these data suggest that high MW HA, when stabilized against degradation, mitigates astrocyte activation in vitro and in vivo. The presence of HA implants was also associated with a significant decrease in CSPG deposition at ten days after SCI. Therefore, HA-based hydrogel systems hold great potential for minimizing undesired scarring as part of future repair strategies after SCI.

  8. High molecular weight hyaluronic acid limits astrocyte activation and scar formation after spinal cord injury.

    PubMed

    Khaing, Zin Z; Milman, Brian D; Vanscoy, Jennifer E; Seidlits, Stephanie K; Grill, Raymond J; Schmidt, Christine E

    2011-08-01

    A major hurdle for regeneration after spinal cord injury (SCI) is the ability of axons to penetrate and grow through the scar tissue. After SCI, inflammatory cells, astrocytes and meningeal cells all play a role in developing the glial scar. In addition, degradation of native high molecular weight (MW) hyaluronic acid (HA), a component of the extracellular matrix, has been shown to induce activation and proliferation of astrocytes. However, it is not known if the degradation of native HA actually enhances glial scar formation. We hypothesize that the presence of high MW HA (HA with limited degradation) after SCI will decrease glial scarring. Here, we demonstrate that high MW HA decreases cell proliferation and reduces chondroitin sulfate proteoglycan (CSPG) production in cultured neonatal and adult astrocytes. In addition, stiffness-matched high MW HA hydrogels crosslinked to resist degradation were implanted in a rat model of spinal dorsal hemisection injury. The numbers of immune cells (macrophages and microglia) detected at the lesion site in animals with HA hydrogel implants were significantly reduced at acute time points (one, three and ten days post-injury). Lesioned animals with HA implants also exhibited significantly lower CSPG expression at ten days post-injury. At nine weeks post-injury, animals with HA hydrogel implants exhibited a significantly decreased astrocytic response, but did not have significantly altered CSPG expression. Combined, these data suggest that high MW HA, when stabilized against degradation, mitigates astrocyte activation in vitro and in vivo. The presence of HA implants was also associated with a significant decrease in CSPG deposition at ten days after SCI. Therefore, HA-based hydrogel systems hold great potential for minimizing undesired scarring as part of future repair strategies after SCI. PMID:21753237

  9. IAPs limit activation of RIP kinases by TNF receptor 1 during development.

    PubMed

    Moulin, Maryline; Anderton, Holly; Voss, Anne K; Thomas, Tim; Wong, Wendy Wei-Lynn; Bankovacki, Aleksandra; Feltham, Rebecca; Chau, Diep; Cook, Wendy D; Silke, John; Vaux, David L

    2012-04-01

    Inhibitor of apoptosis (IAP) proteins cIAP1, cIAP2, and XIAP (X-linked IAP) regulate apoptosis and cytokine receptor signalling, but their overlapping functions make it difficult to distinguish their individual roles. To do so, we deleted the genes for IAPs separately and in combination. While lack of any one of the IAPs produced no overt phenotype in mice, deletion of cIap1 with cIap2 or Xiap resulted in mid-embryonic lethality. In contrast, Xiap(-/-)cIap2(-/-) mice were viable. The death of cIap2(-/-)cIap1(-/-) double mutants was rescued to birth by deletion of tumour necrosis factor (TNF) receptor 1, but not TNFR2 genes. Remarkably, hemizygosity for receptor-interacting protein kinase 1 (Ripk1) allowed Xiap(-/-)cIap1(-/-) double mutants to survive past birth, and prolonged cIap2(-/-)cIap1(-/-) embryonic survival. Similarly, deletion of Ripk3 was able to rescue the mid-gestation defect of cIap2(-/-)cIap1(-/-) embryos, as these embryos survived to E15.5. cIAPs are therefore required during development to limit activity of RIP kinases in the TNF receptor 1 signalling pathway.

  10. 40 CFR Table 2 to Part 455 - Organic Pesticide Active Ingredient Effluent Limitations Best Available Technology Economically...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 29 2010-07-01 2010-07-01 false Organic Pesticide Active Ingredient... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS PESTICIDE CHEMICALS Pt. 455, Table 2 Table 2 to Part 455—Organic Pesticide Active Ingredient Effluent Limitations Best Available Technology Economically...

  11. Assessing Activity Limitations in Patients with Neuromuscular Diseases: Is the ACTIVLIM Questionnaire Linked to ICF and ICF-CY?

    ERIC Educational Resources Information Center

    Raggi, Alberto; Leonardi, Matilde

    2009-01-01

    The objective of this study was to explore to what extent the ACTIVLIM questionnaire, designed to evaluate limitations in activities involving upper and lower limbs in adults and children with neuromuscular diseases, is linked to the domains of the Activities and Participation of the International Classification of Functioning, Disability and…

  12. Factors that Limit and Enable Preschool-Aged Children's Physical Activity on Child Care Centre Playgrounds

    ERIC Educational Resources Information Center

    Coleman, Bianca; Dyment, Janet E.

    2013-01-01

    The incidence of childhood obesity amongst preschool-aged children has increased dramatically in recent years and can be attributed, in part, to a lack of physical activity amongst children in this age group. This study explores the social factors that stand to limit and/or enable children's physical activity opportunities in outdoor settings…

  13. 40 CFR Table 2 to Part 455 - Organic Pesticide Active Ingredient Effluent Limitations Best Available Technology Economically...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 30 2011-07-01 2011-07-01 false Organic Pesticide Active Ingredient... (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS PESTICIDE CHEMICALS Pt. 455, Table 2 Table 2 to Part 455—Organic Pesticide Active Ingredient Effluent Limitations Best Available Technology Economically...

  14. Early Childhood Special Education. "Can I Play Too?" Adapting Common Classroom Activities for Young Children with Limited Motor Abilities.

    ERIC Educational Resources Information Center

    Sheldon, Kristyn

    1996-01-01

    Suggests that teachers are challenged with arranging the environment to allow physically impaired children to participate in classroom activities. Defines limited motor ability. Suggests ways to make minor modifications or adaptations to accommodate these children in common classroom activities, including circle time, art, sensory play, fine…

  15. Slow starch digestion redefined at limit dextrin level by mucosal maltase-glucoamylase and sucrase-isomaltase activities

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Mucosal maltase-glucoamylase (MGAM) and sucrase-isomaltase (SI) digest free glucose from food starches. Amylase (AMY) amplifies these mucosal activities by production of soluble limit dextrins (LDx). This network of enzyme activities determines rate of LDx entry into either the glycemic or the ferme...

  16. A Model for Aryl Hydrocarbon Receptor-Activated Gene Expression Shows Potency and Efficacy Changes and Predicts Squelching Due to Competition for Transcription Co-Activators

    PubMed Central

    Simon, Ted W.; Budinsky, Robert A.; Rowlands, J. Craig

    2015-01-01

    A stochastic model of nuclear receptor-mediated transcription was developed based on activation of the aryl hydrocarbon receptor (AHR) by 2,3,7,8-tetrachlorodibenzodioxin (TCDD) and subsequent binding the activated AHR to xenobiotic response elements (XREs) on DNA. The model was based on effects observed in cells lines commonly used as in vitro experimental systems. Following ligand binding, the AHR moves into the cell nucleus and forms a heterodimer with the aryl hydrocarbon nuclear translocator (ARNT). In the model, a requirement for binding to DNA is that a generic coregulatory protein is subsequently bound to the AHR-ARNT dimer. Varying the amount of coregulator available within the nucleus altered both the potency and efficacy of TCDD for inducing for transcription of CYP1A1 mRNA, a commonly used marker for activation of the AHR. Lowering the amount of available cofactor slightly increased the EC50 for the transcriptional response without changing the efficacy or maximal response. Further reduction in the amount of cofactor reduced the efficacy and produced non-monotonic dose-response curves (NMDRCs) at higher ligand concentrations. The shapes of these NMDRCs were reminiscent of the phenomenon of squelching. Resource limitations for transcriptional machinery are becoming apparent in eukaryotic cells. Within single cells, nuclear receptor-mediated gene expression appears to be a stochastic process; however, intercellular communication and other aspects of tissue coordination may represent a compensatory process to maintain an organism’s ability to respond on a phenotypic level to various stimuli within an inconstant environment. PMID:26039703

  17. Does glaciation act to limit the topography of active mountain belts? Evidence from the Patagonian Andes

    NASA Astrophysics Data System (ADS)

    Thomson, S. N.

    2003-04-01

    Fission-track thermochronological analysis of the Patagonian Andes of southern Chile, particularly in the region of the major intra-arc Liquiñe-Ofqui transpressional fault zone (42° to 46°S), has revealed a complex pattern of late Cenozoic accelerated cooling. The fault zone has been the focus of localised enhanced cooling, attributed to denudation, since ca. 16 to 10 Ma. Several fault blocks can be identified, differentiated by their different cooling histories and total amounts of late Cenozoic cooling. The transpressional nature of this fault zone implies that enhanced cooling was caused by the preferential erosion of variably uplifting fault blocks that formed part of a large, possibly crustal scale "transpressional flower structure". Despite the spatially variable cooling rates and apparent differential denudation across the different fault blocks, the topography (particularly mean and maximum elevation) across these fault blocks is relatively uniform. This implies that this landscape is close to topographic steady-state, such that denudation has managed to approximately balance transpression related rock uplift, despite the spatial variability of the latter during the late Cenozoic. The most dominant denudation process in the Patagonian Andes is glacial erosion. Late Cenozoic glaciation in Patagonia is well known from studies made on the Patagonian ice fields (the third largest in the World). For example, values for the mean equilibrium line altitude (the altitude where annual glacial accumulation and ablation are the same - roughly equivalent to the snowline) can be cited for both the present day and the last glacial maximum. Incorporating these values in to a quantitative analysis of the topography across the different fault blocks using DEM data supports ideas outlined by Brozovic et al. (1997) who quote that where active mountain belts intersect the snowline, the high rates of glacial erosion processes can act at rates sufficient to place a limit on

  18. In-vitro suppression of metabolic activity in malignant human glioblastomas due to pulsed - low frequency electric potential exposures

    NASA Astrophysics Data System (ADS)

    Schlichting, Abby; Waynant, Ronald W.; Tata, Darrell B.

    2010-02-01

    The role of pulsed - low repetition frequency electric potential was investigated in suppressing the metabolic activities of aggressive human brain cancer cells. Twenty four hours post exposure the glioblastomas were found to be significantly inhibited in their metabolic activity. The findings herein reveal a near complete inhibition of glioblastoma's metabolic activity through selective applications of low frequency pulsed electric potentials.

  19. Upper Limits of Normal for Alanine Aminotransferase Activity in the United States Population

    PubMed Central

    Ruhl, Constance E.; Everhart, James E.

    2011-01-01

    Background & Rationale Alanine aminotransferase (ALT) is an important test for liver disease, yet there is no generally accepted upper limit of normal (ULN) in the United States. Furthermore, the ability of ALT to differentiate persons with and without liver disease is uncertain. We examined cut-offs for ALT for their ability to discriminate between persons with positive hepatitis C virus (HCV) RNA and those at low risk for liver injury in the U.S. population. Methods Among adult participants in the 1999–2008 U.S. National Health and Nutrition Examination Survey, 259 were positive for serum HCV RNA and 3,747 were at low risk for liver injury (negative HCV RNA and hepatitis B surface antigen, low alcohol consumption, no evidence of diabetes, normal body mass index and waist circumference). Serum ALT activity was measured centrally. Results Maximum correct classification was achieved at ALT=29 IU/L for men (88% sensitivity, 83% specificity) and 22 (89% sensitivity, 82% specificity) for women. The cut-off for 95% sensitivity was an ALT=24 IU/L (70% specificity) for men and 18 (63% specificity) for women. The cut-off for 95% specificity was an ALT=44 IU/L (64% sensitivity) for men and 32 (59% sensitivity) for women. The area under the curve was 0.929 for men and 0.915 for women. If the cut-offs with the best correct classification were applied to the entire population, 36.4% of men and 28.3% of women would have had abnormal ALT. Conclusion ALT discriminates persons infected with HCV from those at low risk of liver disease, but would be considered elevated in a large proportion of the U.S. population. PMID:21987480

  20. Investigations of the use of bioavailability data to adjust occupational exposure limits for active pharmaceutical ingredients.

    PubMed

    Naumann, Bruce D; Weideman, Patricia A; Sarangapani, Ramesh; Hu, Shu-Cheih; Dixit, Rakesh; Sargent, Edward V

    2009-11-01

    Occupational exposure limits (OELs) for active pharmaceutical ingredients have traditionally been established using no-observed-adverse-effect levels derived from clinical studies employing po and iv routes of administration and by applying default uncertainty factors or chemical-specific adjustment factors. However, exposure by the inhalation or dermal route is more relevant in terms of occupational safety. In this investigation, to explore new methods for route-to-route extrapolation, the bioavailability of MK-0679, a leukotriene D(4) receptor antagonist, was compared following iv, po, intranasal (in), or intratracheal (it) administration. The relative bioavailability of MK-0679 was iv congruent with it > po congruent with in. Bioavailability correction factors (BCFs) of 2.0 and 0.6 were derived from these data to adjust a hypothetical OEL of 0.1 mg/m(3) for MK-0679 with particle sizes of 10 and 50 mum, respectively. These BCFs were used to adjust the OEL established using po clinical data, to reflect the differences in bioavailability following deposition in different regions of the respiratory tract. To further investigate how bioavailability data could be used in setting OELs, a preliminary pharmacokinetic (PK) model was developed to describe the time course of plasma concentrations using the data from the route comparison study. An inhalation study was then performed to test the validity of using either empirical data or modeling approaches to derive BCFs when setting OELs. These investigations demonstrated how the use of route-specific PK data could reduce some of the uncertainties associated with route-to-route extrapolation and allow for improved precision and quantitative adjustments when establishing OELs. Further investigations are needed to better understand the factors responsible for differences in systemic uptake following deposition in different regions of the respiratory tract and how these can be generalized across different classes of soluble

  1. High contrast imaging with an arbitrary aperture: active correction of aperture discontinuities: fundamental limits and practical trades offs

    NASA Astrophysics Data System (ADS)

    Pueyo, Laurent; Norman, Colin Arthur; Soummer, Remi; Perrin, Marshall D.; N'Diaye, Mamadou; Choquet, Elodie

    2015-01-01

    In a recent paper we discussed a new method to achieve high-contrast images using segmented and/or on-axis telescopes. Our approach, named Active Compensation of Aperture Discontinuities (ACAD) relies on two sequential Deformable Mirrors to compensate for the large amplitude excursions in the telescope aperture due to secondary support structures and/or segment gaps. In this configuration the parameter landscape of Deformable Mirror Surfaces that yield high contrast Point Spread Functions is not linear, and non-linear methods are needed to find the true minimum. In particular we showed that broadband high contrast solutions can be achieved using realistic surface deformations that are accessible using existing technologies for a variety of telescope pupil geometries. In this paper we first focus on the fundamental limits and practical trade-offs associated with ACAD. In a first part we will study the fundamental limits and practical tradeoffs associated with ACAD, regardless of the downstream coronagraphic architecture. The mathematical techniques to finding ACAD DM shapes require to solve a complex differential equation. We will first discuss the scaling laws underlying this non-linear solution and their impact of DM placement and geometry wishing the optical design of an instrument. We will then consider the sensitivity to low order aberrations: in principle an ACAD solution that comprises large strokes will be more sensitive to these aberrations than one with smaller strokes. As a consequence, we will quantify this sensitive both using analytical models and numerical simulations. We will present diffractive end to end simulations and quantify the ultimate contrast and bandwidth achievable with ACAD, which can be reached by superposing using a classical linear wavefront control algorithms on top of the Monge Ampere solution. Finally, recent work has shown that coronagraph designs can also accommodate for secondary support structures and/or segments gaps, at a

  2. Active surveillance of visual impairment due to adverse drug reactions: findings from a national study in the United Kingdom

    PubMed Central

    Cumberland, Phillippa M; Russell-Eggitt, Isabelle; Rahi, Jugnoo S

    2015-01-01

    As visual impairment (VI) due to adverse drug reactions (ADR) is rare in adults and children, there is an incomplete evidence base to inform guidance for screening and for counseling patients on the potential risks of medications. We report on suspected drugs and the eye conditions found in a national study of incidence of diagnosis of visual impairment due to suspected ADR. Case ascertainment was via the British Ophthalmological Surveillance Unit (BOSU), between March 2010 and February 2012, with follow-up after 6 months. Case definition: any child or adult with bilateral or unilateral visual impairment due to a suspected ADR, using distance acuity worse than Snellen 6/18 (logMAR 0.48) in the better eye (bilateral) or affected eye (unilateral). Anonymized patient information on potential cases was provided by managing ophthalmologists, comprising visual status before and after suspected ADR, ophthalmic condition attributable to the ADR, preexisting eye disease and prescribed medications at the time of the ADR. Permanency and causality of the visual impairment were confirmed by the managing clinician, after 6 months, using the WHO Uppsala Monitoring Committee criteria. Over 2 years, 36 eligible cases were reported of whom 23 had permanent VI. While most cases were due to drugs known to have adverse side-effects, some were unanticipated sporadic cases. Visual impairment due to ADRs is rare. However, with for example, increasing polypharmacy in the elderly, monitoring of ocular ADRs, although challenging, is necessary. PMID:25692024

  3. VS411 Reduced Immune Activation and HIV-1 RNA Levels in 28 Days: Randomized Proof-of-Concept Study for AntiViral-HyperActivation Limiting Therapeutics

    PubMed Central

    Lori, Franco; De Forni, Davide; Katabira, Elly; Baev, Denis; Maserati, Renato; Calarota, Sandra A.; Cahn, Pedro; Testori, Marco; Rakhmanova, Aza; Stevens, Michael R.

    2012-01-01

    Background A new class of antiretrovirals, AntiViral-HyperActivation Limiting Therapeutics (AV-HALTs), has been proposed as a disease-modifying therapy to both reduce Human Immunodeficiency Virus Type 1 (HIV-1) RNA levels and the excessive immune activation now recognized as the major driver of not only the continual loss of CD4+ T cells and progression to Acquired Immunodeficiency Syndrome (AIDS), but also of the emergence of both AIDS-defining and non-AIDS events that negatively impact upon morbidity and mortality despite successful (ie, fully suppressive) therapy. VS411, the first-in-class AV-HALT, combined low-dose, slow-release didanosine with low-dose hydroxycarbamide to accomplish both objectives with a favorable toxicity profile during short-term administration. Five dose combinations were administered as VS411 to test the AV-HALT Proof-of-Concept in HIV-1-infected subjects. Methods Multinational, double-blind, 28-day Phase 2a dose-ranging Proof-of-Concept study of antiviral activity, immunological parameters, safety, and genotypic resistance in 58 evaluable antiretroviral-naïve HIV-1-infected adults. Randomization and allocation to study arms were carried out by a central computer system. Results were analyzed by ANOVA, Kruskal-Wallis, ANCOVA, and two-tailed paired t tests. Results VS411 was well-tolerated, produced significant reductions of HIV-1 RNA levels, increased CD4+ T cell counts, and led to significant, rapid, unprecedented reductions of immune activation markers after 28 days despite incomplete viral suppression and without inhibiting HIV-1-specific immune responses. The didanosine 200 mg/HC 900 mg once-daily formulation demonstrated the greatest antiviral efficacy (HIV-1 RNA: −1.47 log10 copies/mL; CD4+ T cell count: +135 cells/mm3) and fewest adverse events. Conclusions VS411 successfully established the Proof-of-Concept that AV-HALTs can combine antiviral efficacy with rapid, potentially beneficial reductions in the excessive immune system

  4. 77 FR 75660 - Agency Information Collection Activities: Proposed Collection; Comments Requested: Limited...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-21

    ... Collection; Comments Requested: Limited Permittee Transaction Report ACTION: 60-day notice. The Department of... Transaction Report. (3) Agency form number, if any, and the applicable component of the Department of...

  5. A new 10Be record recovered from an Antarctic ice core: validity and limitations to record the solar activity

    NASA Astrophysics Data System (ADS)

    Baroni, Mélanie; Bard, Edouard; Aster Team

    2015-04-01

    Cosmogenic nuclides provide the only possibility to document solar activity over millennia. Carbon-14 (14C) and beryllium-10 (10Be) records are retrieved from tree rings and ice cores, respectively. Recently, 14C records have also proven to be reliable to detect two large Solar Proton Events (SPE) (Miyake et al., Nature, 2012, Miyake et al., Nat. Commun., 2013) that occurred in 774-775 A.D. and in 993-994 A.D.. The origin of these events is still under debate but it opens new perspectives for the interpretation of 10Be ice core records. We present a new 10Be record from an ice core from Dome C (Antarctica) covering the last millennium. The chronology of this new ice core has been established by matching volcanic events on the WAIS Divide ice core (WDC06A) that is the best dated record in Antarctica over the Holocene (Sigl et al., JGR, 2013, Sigl et al., Nat. Clim. Change, 2014). The five minima of solar activity (Oort, Wolf, Spörer, Maunder and Dalton) are detected and characterized by a 10Be concentration increase of ca. 20% above average in agreement with previous studies of ice cores drilled at South Pole and Dome Fuji in Antarctica (Bard et al., EPSL, 1997; Horiuchi et al., Quat. Geochrono., 2008) and at NGRIP and Dye3 in Greenland (Berggren et al., GRL, 2009). The high resolution, on the order of a year, allows the detection of the 11-year solar cycle. Sulfate concentration, a proxy for volcanic eruptions, has also been measured in the very same samples, allowing a precise comparison of both 10Be and sulfate profiles. We confirm the systematic relationship between stratospheric eruptions and 10Be concentration increases, first evidenced by observations of the stratospheric volcanic eruptions of Agung in 1963 and Pinatubo in 1991 (Baroni et al., GCA, 2011). This relationship is due to an increase in 10Be deposition linked to the role played by the sedimentation of volcanic aerosols. In the light of these new elements, we will discuss the limitations and

  6. Patients' experiences of physical limitations in daily life activities when suffering from chronic heart failure; a phenomenographic analysis.

    PubMed

    Pihl, Emma; Fridlund, Bengt; Mårtensson, Jan

    2011-03-01

    The aim of the study was to describe how patients suffering from chronic heart failure conceived their physical limitations in daily life activities. An explorative and qualitative design with a phenomenographic approach was chosen, a total of 15 patients were interviewed. The findings indicate that participants perceived a variety of structural aspects pertaining to physical limitations in activities of daily life which resulted in four referential aspects. Need of finding practical solutions in daily life focused on how life had to be changed and other ways of performing activities of daily life had to be invented. Having realistic expectations about the future was characterised by belief that the future itself would be marked by change in physical functioning, but an incentive to maintain functions and activities ensured good quality of or even increased capacity in daily life. Not believing in one's own ability included the perception of having no opportunity to improve ability to perform activities of daily life. There were perceptions of undesired passivity, undefined fear of straining themselves or performing activities that could endanger their health in addition to uncertainty about the future. In Losing one's social role in daily life, participants described losing their social network and their position in society and family because of limited physical capacity. A lack of important issues, mental and physical, occurred when physical capacity was lost. In conclusion, patients suffering from chronic heart failure found new solutions to manage activities in daily life, including willingness to change focus and identify other ways of doing important things. Patients had an incentive to maintain functions and activities to ensure a good quality of and strengthen their physical capacity in daily life. Inability to trust in their physical capacity in combination with experienced limitations in daily life prevented patients from attempting to increase activities

  7. The total protein content, protein fractions and proteases activities of drone prepupae of Apis mellifera due to varrosis.

    PubMed

    Zółtowska, Krystyna; Lipiński, Zbigniew; Dmitryjuk, Małgorzata

    2005-01-01

    The proteins level and activities of acid and alkaline proteases in whole body extracts of drone prepupae of Apis mellifera naturally infested with Varroa destructor were studied. The infested and a non-infested group did not differ significantly in their total protein content. However, some differences in protein profiles were found. A lack of three protein fractions of moderate and lower molecular weight in infested prepupae was noted. Moreover, some differences in the quantity of protein in most of the fractions were observed. The activity of acid proteases from infested prepupae was lower (p < 0.05) compared with the activity of these proteases from the non-infested one group. The infested drone had higher activity of alkaline proteases than non-infested but this difference was not statisticaly significant.

  8. The total protein content, protein fractions and proteases activities of drone prepupae of Apis mellifera due to varrosis.

    PubMed

    Zółtowska, Krystyna; Lipiński, Zbigniew; Dmitryjuk, Małgorzata

    2005-01-01

    The proteins level and activities of acid and alkaline proteases in whole body extracts of drone prepupae of Apis mellifera naturally infested with Varroa destructor were studied. The infested and a non-infested group did not differ significantly in their total protein content. However, some differences in protein profiles were found. A lack of three protein fractions of moderate and lower molecular weight in infested prepupae was noted. Moreover, some differences in the quantity of protein in most of the fractions were observed. The activity of acid proteases from infested prepupae was lower (p < 0.05) compared with the activity of these proteases from the non-infested one group. The infested drone had higher activity of alkaline proteases than non-infested but this difference was not statisticaly significant. PMID:16841690

  9. A constitutive active MAPK/ERK pathway due to BRAFV600E positively regulates AHR pathway in PTC

    PubMed Central

    Regazzo, Daniela; Bertazza, Loris; Galuppini, Francesca; Guzzardo, Vincenza; Jaffrain-Rea, Marie Lise; Vianello, Federica; Ciato, Denis; Ceccato, Filippo; Watutantrige-Fernando, Sara; Bisognin, Andrea; Bortoluzzi, Stefania; Pennelli, Gianmaria; Boscaro, Marco; Scaroni, Carla; Mian, Caterina

    2015-01-01

    The aryl hydrocarbon receptor (AHR) is a ligand-activated transcription factor mediating the toxicity and tumor-promoting properties of dioxin. AHR has been reported to be overexpressed and constitutively active in a variety of solid tumors, but few data are currently available concerning its role in thyroid cancer. In this study we quantitatively explored a series of 51 paired-normal and papillary thyroid carcinoma (PTC) tissues for AHR-related genes. We identified an increased AHR expression/activity in PTC, independently from its nuclear dimerization partner and repressor but strictly related to a constitutive active MAPK/ERK pathway. The AHR up-regulation followed by an increased expression of AHR target genes was confirmed by a meta-analysis of published microarray data, suggesting a ligand-independent active AHR pathway in PTC. In-vitro studies using a PTC-derived cell line (BCPAP) and HEK293 cells showed that BRAFV600E may directly modulate AHR localization, induce AHR expression and activity in an exogenous ligand-independent manner. The AHR pathway might represent a potential novel therapeutic target for PTC in the clinical practice. PMID:26392334

  10. The effects on community college student physics achievement and attitudes about learning physics due to inquiry-based laboratory activities versus cookbook laboratory activities

    NASA Astrophysics Data System (ADS)

    Nock, George Allen Brittingham

    The purpose of this quasi-experimental study was to determine the effects on community college student physics conceptual achievement and attitudes about learning physics due to the use of inquiry-based laboratory activities versus cookbook laboratory activities. An analysis of covariance (ANCOVA) was performed to test for differences in mean post-test Force Concept Inventory (FCI) score for two different types of physics lab instruction (IL versus CBL). Results of the ANCOVA, F (1, 35) = 0.761, p < 0.389, supported the null hypothesis that no significant difference was found in the post-test FCI scores of the two groups. An ANCOVA was performed to test for differences in mean post-test Mechanics Baseline Test (MBT) score for two different types of physics lab instruction (IL versus CBL)., however, the covariate and the dependent variable were shown to not be linearly related. Therefore, a one-way analysis of variance (ANOVA) was used to compare MBT scores. The results of the ANOVA, F (1, 36) = 0.066, p < 0.798, supported the null hypothesis that there was no significant difference in MBT scores of the two groups. A step-wise multiple linear regression was used to analyze the relationships between the FCI post-test score and the type of instruction, FCI pre-test score, and American College Test (ACT) science reasoning sub-scores. The FCI pre-test score and ACT science score were shown to be the best predictors of FCI post-test score. Another step-wise multiple linear regression was used to analyze the relationships between the MBT post-test score and type of instruction, MBT pre-test score, and ACT science reasoning sub-scores. The ACT Science sub-scores were determined to be the best predictor of MBT post-test score. An independent t-test was used to compare the mean lecture test grades for the lab groups taught using inquiry and cookbook methods. The mean lecture test scores of the inquiry-based lab group (M = 81.39, S.D. = 8.15) were found to be significantly

  11. Interruption pf physcial activity due to illness in the Lifestyle Interventions and Indepencence for Elders Pilot (LIFE-P) trial

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Lifestyle Interventions and Independence for Elders Pilot (LIFE-P) was a trial to examine the effects of physical activity (PA) compared to a health education control on measures of disability in sedentary older adults. Medical suspensions were examined for the first 12 months of the trial in th...

  12. Improving Active and Passive Avoidance Memories Deficits Due to Permanent Cerebral Ischemia by Pomegranate Seed Extract in Female Rats

    PubMed Central

    Sarkaki, Alireza; Rezaiei, Moslem; Gharib naseri, MohammadKazem; Rafieirad, Maryam

    2013-01-01

    Background: This study aimed to evaluate the effect of two weeks oral administration of pomegranate seed extract (PGSE) on active and passive avoidance memories after permanent bilateral common carotid arteries occlusion (2CCAO) to induce permanent cerebral ischemia in adult female rats. Methods: Seventy adult female Wistar rats (250 ± 20 g) were used. Animals were divided randomly into seven groups with 10 in each: 1) Sham-operated; 2) Ischemic; 3–6) Ischemic received PGSE (100, 200, 400, and 800 mg/2mL/kg, orally) for 14 days; 7) Ischemic received vehicle. In order to create 2CCAO, carotid arteries were ligatured and then cut bilaterally. Active and passive avoidance task were measured using criterion condition responses (CCRs) in Y-maze and step-through latency (STL) in two-way shuttle box in all female rats. Results: Both active and passive avoidance memories were significantly impaired in rats after cerebral hypoxia-ischemia (CHI) (P < 0.001). PGSE treatment significantly improved passive and active memory impairments with 2CCAO (P < 0.05, P < 0.01, and P < 0.001). No toxicity was observed even with high-dose PGSE consumption (800 mg/kg, for 14 days). Conclusion: PGSE exhibits therapeutic potential for avoidance memories, which is most likely related at least in part to its antioxidative and free radical scavenging actions. PMID:23983574

  13. 30 CFR 585.521 - Do my financial assurance requirements change as activities progress on my limited lease or grant?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... monetary obligations; and (4) The estimated cost of facility decommissioning. (b) You may satisfy the... the level of your financial assurance as activities progress on your limited lease or grant. We will base the determination for the amount of financial assurance requirements on our estimate of the...

  14. 30 CFR 585.521 - Do my financial assurance requirements change as activities progress on my limited lease or grant?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... monetary obligations; and (4) The estimated cost of facility decommissioning. (b) You may satisfy the... the level of your financial assurance as activities progress on your limited lease or grant. We will base the determination for the amount of financial assurance requirements on our estimate of the...

  15. 30 CFR 585.521 - Do my financial assurance requirements change as activities progress on my limited lease or grant?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... monetary obligations; and (4) The estimated cost of facility decommissioning. (b) You may satisfy the... the level of your financial assurance as activities progress on your limited lease or grant. We will base the determination for the amount of financial assurance requirements on our estimate of the...

  16. The Importance of Motor Functional Levels from the Activity Limitation Perspective of ICF in Children with Cerebral Palsy

    ERIC Educational Resources Information Center

    Mutlu, Akmer

    2010-01-01

    Our purpose in this study was to evaluate performance and capacity as defined by Gross Motor Function Classification System (GMFCS) and Manual Ability Classification System (MACS) from the "activity limitation" perspective of International Classification of Functioning, Disability, and Health (ICF) and to investigate the relationship between the…

  17. 78 FR 73823 - Subzone 38E, Authorization of Limited Production Activity, Black & Decker (U.S.) Inc., (Power...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-09

    ... Foreign-Trade Zones Board Subzone 38E, Authorization of Limited Production Activity, Black & Decker (U.S.) Inc., (Power Tools), Fort Mill, SC On July 19, 2013, Black & Decker (U.S.) Inc. submitted a... comment (78 FR 45911-45912, 7-30-2013). The FTZ Board has determined that further review of part of...

  18. Fast skeletal muscle troponin activation increases force of mouse fast skeletal muscle and ameliorates weakness due to nebulin-deficiency.

    PubMed

    Lee, Eun-Jeong; De Winter, Josine M; Buck, Danielle; Jasper, Jeffrey R; Malik, Fady I; Labeit, Siegfried; Ottenheijm, Coen A; Granzier, Henk

    2013-01-01

    The effect of the fast skeletal muscle troponin activator, CK-2066260, on calcium-induced force development was studied in skinned fast skeletal muscle fibers from wildtype (WT) and nebulin deficient (NEB KO) mice. Nebulin is a sarcomeric protein that when absent (NEB KO mouse) or present at low levels (nemaline myopathy (NM) patients with NEB mutations) causes muscle weakness. We studied the effect of fast skeletal troponin activation on WT muscle and tested whether it might be a therapeutic mechanism to increase muscle strength in nebulin deficient muscle. We measured tension-pCa relations with and without added CK-2066260. Maximal active tension in NEB KO tibialis cranialis fibers in the absence of CK-2066260 was ∼60% less than in WT fibers, consistent with earlier work. CK-2066260 shifted the tension-calcium relationship leftwards, with the largest relative increase (up to 8-fold) at low to intermediate calcium levels. This was a general effect that was present in both WT and NEB KO fiber bundles. At pCa levels above ∼6.0 (i.e., calcium concentrations <1 µM), CK-2066260 increased tension of NEB KO fibers to beyond that of WT fibers. Crossbridge cycling kinetics were studied by measuring k(tr) (rate constant of force redevelopment following a rapid shortening/restretch). CK-2066260 greatly increased k(tr) at submaximal activation levels in both WT and NEB KO fiber bundles. We also studied the sarcomere length (SL) dependence of the CK-2066260 effect (SL 2.1 µm and 2.6 µm) and found that in the NEB KO fibers, CK-2066260 had a larger effect on calcium sensitivity at the long SL. We conclude that fast skeletal muscle troponin activation increases force at submaximal activation in both wildtype and NEB KO fiber bundles and, importantly, that this troponin activation is a potential therapeutic mechanism for increasing force in NM and other skeletal muscle diseases with loss of muscle strength. PMID:23437068

  19. Limitation of dietary copper and zinc decreases superoxide dismutase activity in the onion fly, Delia antiqua.

    PubMed

    Matsuo, T; Ooe, S; Ishikawa, Y

    1997-06-01

    Larvae of the onion fly, Delia antiqua, have lower superoxide dismutase (SOD) activity when they are fed a defined synthetic diet that contains no copper or zinc. SOD activity was rapidly recovered when these larvae were fed onion bulbs. Addition of copper and zinc to the synthetic diet also led to the recovery of SOD activity. Results of an immunoblotting analysis using anti-D. antiqua CuZnSOD mouse monoclonal antibody suggest that this alteration of SOD activity is dependent on the amount of CuZnSOD. PMID:9172377

  20. 49 CFR 40.355 - What limitations apply to the activities of service agents?

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... (including, but not limited to, collections, laboratory testing, MRO, and SAP services). No one may do so on... in the transmission of individual SAP reports to the actual employer. That is, the SAP may not send... individual SAP summary reports and follow-up testing plans after they are sent to the DER, and the SAP...

  1. 49 CFR 40.355 - What limitations apply to the activities of service agents?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... (including, but not limited to, collections, laboratory testing, MRO, and SAP services). No one may do so on... in the transmission of individual SAP reports to the actual employer. That is, the SAP may not send... individual SAP summary reports and follow-up testing plans after they are sent to the DER, and the SAP...

  2. Classifying and assembling two-dimensional X-ray laser diffraction patterns of a single particle to reconstruct the three-dimensional diffraction intensity function: resolution limit due to the quantum noise

    SciTech Connect

    Tokuhisa, Atsushi; Taka, Junichiro; Kono, Hidetoshi; Go, Nobuhiro

    2012-05-01

    A new algorithm is developed for reconstructing the high-resolution three-dimensional diffraction intensity function of a globular biological macromolecule from many quantum-noise-limited two-dimensional X-ray laser diffraction patterns, each for an unknown orientation. The structural resolution is expressed as a function of the incident X-ray intensity and quantities characterizing the target molecule. A new two-step algorithm is developed for reconstructing the three-dimensional diffraction intensity of a globular biological macromolecule from many experimentally measured quantum-noise-limited two-dimensional X-ray laser diffraction patterns, each for an unknown orientation. The first step is classification of the two-dimensional patterns into groups according to the similarity of direction of the incident X-rays with respect to the molecule and an averaging within each group to reduce the noise. The second step is detection of common intersecting circles between the signal-enhanced two-dimensional patterns to identify their mutual location in the three-dimensional wavenumber space. The newly developed algorithm enables one to detect a signal for classification in noisy experimental photon-count data with as low as ∼0.1 photons per effective pixel. The wavenumber of such a limiting pixel determines the attainable structural resolution. From this fact, the resolution limit due to the quantum noise attainable by this new method of analysis as well as two important experimental parameters, the number of two-dimensional patterns to be measured (the load for the detector) and the number of pairs of two-dimensional patterns to be analysed (the load for the computer), are derived as a function of the incident X-ray intensity and quantities characterizing the target molecule.

  3. Study of the function of sarcoplasmic reticulum of vascular smooth muscle during activation due to depolarization-induced calcium influx

    SciTech Connect

    Hwang, K.S.

    1987-01-01

    The role of sarcoplasmic reticulum (SR) in vascular smooth muscle was evaluated with respect to regulation of myoplasmic Ca{sup 2+} during the Ca{sup 2+} entry induced by depolarization. Calcium agonist, Bay K8644, stimulated Ca{sup 2+} influx as well as tension in physiological salt solution, (PSS) in contrast to the priming effects due to the depolarization originally reported. Disparity, however, was found between the Ca{sup 2+} entered and tension developed. Correlation between the tension and {sup 45}Ca influx showed a typical threshold phenomenon; the basal Ca{sup 2+} influx can be raised to a certain level (25%) without tension induction, after which a minor increase in Ca{sup 2+} influx produced significant tension. This subthreshold Ca{sup 2+} influx was found accumulated in the caffeine-sensitive Ca stores, the SR. This confirmed the dependency of tension on the rate of Ca{sup 2+} entry demonstrated by a previous report.

  4. Prevalence and work-related risk factors for reduced activities and absenteeism due to low back symptoms.

    PubMed

    Widanarko, Baiduri; Legg, Stephen; Stevenson, Mark; Devereux, Jason; Eng, Amanda; 't Mannetje, Andrea; Cheng, Soo; Pearce, Neil

    2012-07-01

    Although quite a lot is known about the risk factors for low back symptoms (LBS), less is known about the risk factors for the consequences of LBS. A sample of 3003 men and women randomly selected from the New Zealand Electoral Roll, were interviewed by telephone about self reported physical, psychosocial, organizational, environmental factors and the consequences of LBS (i.e. self-reported reduced activities and absenteeism). The 12-month period prevalence of reduced activities and absenteeism were 18% and 9%, respectively. Lifting (OR 1.79 95% CI 1.16-2.77) increased the risk of reduced activities. Working in awkward/tiring positions (OR 2.11 95% CI 1.20-3.70) and in a cold/damp environment (OR 2.18 95% CI 1.11-4.28) increased the risk of absenteeism. Among those with LBS, reduced activities increased with working in a hot/warm environment (OR 2.14 95% CI 1.22-3.76) and absenteeism was increased with work in awkward/tiring positions (OR 2.06 95% CI 1.13-3.77), tight deadlines (OR 1.89 95% CI 1.02-3.50), and a hot/warm environment (OR 3.35 95% CI 1.68-6.68). Interventions to reduce the consequences of LBS should aim to reduce awkward/tiring positions, lifting and work in a cold/damp environment. For individuals with LBS, additional focus should be to reduce tight deadlines, and work in hot/warm environments. PMID:22123534

  5. Prevalence and work-related risk factors for reduced activities and absenteeism due to low back symptoms.

    PubMed

    Widanarko, Baiduri; Legg, Stephen; Stevenson, Mark; Devereux, Jason; Eng, Amanda; 't Mannetje, Andrea; Cheng, Soo; Pearce, Neil

    2012-07-01

    Although quite a lot is known about the risk factors for low back symptoms (LBS), less is known about the risk factors for the consequences of LBS. A sample of 3003 men and women randomly selected from the New Zealand Electoral Roll, were interviewed by telephone about self reported physical, psychosocial, organizational, environmental factors and the consequences of LBS (i.e. self-reported reduced activities and absenteeism). The 12-month period prevalence of reduced activities and absenteeism were 18% and 9%, respectively. Lifting (OR 1.79 95% CI 1.16-2.77) increased the risk of reduced activities. Working in awkward/tiring positions (OR 2.11 95% CI 1.20-3.70) and in a cold/damp environment (OR 2.18 95% CI 1.11-4.28) increased the risk of absenteeism. Among those with LBS, reduced activities increased with working in a hot/warm environment (OR 2.14 95% CI 1.22-3.76) and absenteeism was increased with work in awkward/tiring positions (OR 2.06 95% CI 1.13-3.77), tight deadlines (OR 1.89 95% CI 1.02-3.50), and a hot/warm environment (OR 3.35 95% CI 1.68-6.68). Interventions to reduce the consequences of LBS should aim to reduce awkward/tiring positions, lifting and work in a cold/damp environment. For individuals with LBS, additional focus should be to reduce tight deadlines, and work in hot/warm environments.

  6. Optical Modeling Activities for NASA's James Webb Space Telescope (JWST). 3; Wavefront Aberrations due to Alignment and Figure Compensation

    NASA Technical Reports Server (NTRS)

    Howard, Joseph

    2007-01-01

    This is part three of a series describing the ongoing optical modeling activities for James Webb Space Telescope (JWST). The first two discussed modeling JWST on-orbit performance using wavefront sensitivities to predict line of sight motion induced blur, and stability during thermal transients. The work here investigates the aberrations resulting from alignment and figure compensation of the controllable degrees of freedom (primary and secondary mirrors), which may be encountered during ground alignment and on-orbit commissioning of the observatory. The optical design of the telescope is a three-mirror anastigmat, with an active fold mirror at the exit pupil for fine guiding. The primary mirror is over 6.5 meters in diameter, and is composed of 18 hexagonal segments that can individually positioned on hexapods, as well as compensated for radius of curvature. This effectively gives both alignment and figure control of the primary mirror. The secondary mirror can be moved in rigid body only, giving alignment control of the telescope. The tertiary mirror is fixed, however, as well as the location of the science instrumentation. Simulations are performed of various combinations of active alignment corrections of component figure errors, and of primary mirror figure corrections of alignment errors. Single field point and moderate field knowledge is assumed in the corrections. Aberrations over the field are reported for the varying cases, and examples presented.

  7. Indications for different types of brittle failure due to active coal mining using waveform similarities of induced seismic events

    NASA Astrophysics Data System (ADS)

    Wehling-Benatelli, S.; Becker, D.; Bischoff, M.; Friederich, W.; Meier, T.

    2013-10-01

    Longwall mining activity in the Ruhr coal mining district leads to mining-induced seismicity. For detailed studies the seismicity of a single longwall panel beneath the town of Hamm-Herringen in the eastern Ruhr area was monitored between June 2006 and July 2007 with a dense temporary network of 15 seismic stations. More than 7000 seismic events with magnitudes between -1.7 ≤ ML ≤ 2.0 were detected and localized in this period. Most of the events occurred in the vicinity of the moving longwall face. In order to find possible differences in the brittle failure types of these events an association of the events to distinct clusters is performed based on their waveform characteristics. This task is carried out using a new clustering algorithm utilizing a network similarity matrix which is created by combining all available 3-component single station similarity matrices. The resultant network matrix is then sorted with respect to the similarity of its rows leading to a sorted matrix immediately indicating the clustering of the event catalogue. Finally, clusters of similar events are extracted by visual inspection. This approach results in the identification of several large clusters which are distinct with respect to their spatial and temporal characteristics as well as their frequency magnitude distributions. Comparable clusters are also found with a conventional single linkage approach, however, the new routine seems to be able to associate more events to specific clusters without merging the clusters. The nine largest observed clusters can be tentatively divided into three different groups that indicate different types of brittle failure. The first group consists of the two largest clusters which constitute more than half of all recorded events. Results of a relative relocation using cross-correlation data suggest that these events are confined to the extent of the mined out longwall and cluster close to the edges of the active longwall at the depth of active

  8. Indications for different types of brittle failure due to active coal mining using waveform similarities of induced seismic events

    NASA Astrophysics Data System (ADS)

    Wehling-Benatelli, S.; Becker, D.; Bischoff, M.; Friederich, W.; Meier, T.

    2013-05-01

    Longwall mining activity in the Ruhr-coal mining district leads to mining-induced seismicity. For detailed studies seismicity of a single longwall panel beneath the town of Hamm-Herringen in the eastern Ruhr area was monitored between June 2006 and July 2007 with a dense temporary array of 15 seismic stations. More than 7000 seismic events with magnitudes between -1.7 ≤ ML ≤ 2.0 were detected and localized in this period. Most of the events occurred in the vicinity of the moving longwall face. In order to find possible differences in the brittle failure types of these events an association of the events to distinct clusters based on their waveform characteristics is performed. This task is carried out using a new clustering algorithm utilizing a network similarity matrix which is created by combining all available 3-component single station similarity matrices. The resultant network matrix is then sorted with respect to the similarity of its rows leading to a sorted matrix immediately indicating the clustering of the event catalogue. Finally, clusters of similar events are extracted by visual inspection. This approach results in the identification of several large clusters which are distinct with respect to their spatial and temporal characteristics as well as their frequency magnitude distributions. Comparable clusters are also found with a conventional single linkage approach, however, the new routine seems to be able to associate more events to specific clusters without merging the clusters. The nine largest observed clusters can be tentatively divided into three different groups that indicate different types of brittle failure. The first group consists of the two largest clusters which constitute more than half of all recorded events. Results of a relative relocation using cross correlation data suggest that these events are confined to the extent of the mined out longwall and cluster close to the edges of the active longwall at the depth of active

  9. Synergistic transcriptional activation by CTF/NF-I and the estrogen receptor involves stabilized interactions with a limiting target factor.

    PubMed Central

    Martinez, E; Dusserre, Y; Wahli, W; Mermod, N

    1991-01-01

    Transcription initiation at eukaryotic protein-coding gene promoters is regulated by a complex interplay of site-specific DNA-binding proteins acting synergistically or antagonistically. Here, we have analyzed the mechanisms of synergistic transcriptional activation between members of the CCAAT-binding transcription factor/nuclear factor I (CTF/NF-I) family and the estrogen receptor. By using cotransfection experiments with HeLa cells, we show that the proline-rich transcriptional activation domain of CTF-1, when fused to the GAL4 DNA-binding domain, synergizes with each of the two estrogen receptor-activating regions. Cooperative DNA binding between the GAL4-CTF-1 fusion and the estrogen receptor does not occur in vitro, and in vivo competition experiments demonstrate that both activators can be specifically inhibited by the overexpression of a proline-rich competitor, indicating that a common limiting factor is mediating their transcriptional activation functions. Furthermore, the two activators functioning synergistically are much more resistant to competition than either factor alone, suggesting that synergism between CTF-1 and the estrogen receptor is the result of a stronger tethering of the limiting target factor(s) to the two promoter-bound activators. Images PMID:2038313

  10. Steps toward validity in active living research: research design that limits accusations of physical determinism.

    PubMed

    Riggs, William

    2014-03-01

    "Active living research" has been accused of being overly "physically deterministic" and this article argues that urban planners must continue to evolve research and address biases in this area. The article first provides background on how researchers have dealt with the relationship between the built environment and health over years. This leads to a presentation of how active living research might be described as overly deterministic. The article then offers lessons for researchers planning to embark in active-living studies as to how they might increase validity and minimize criticism of physical determinism.

  11. Inversed relationship between CD44 variant and c-Myc due to oxidative stress-induced canonical Wnt activation

    SciTech Connect

    Yoshida, Go J. Saya, Hideyuki

    2014-01-10

    Highlights: •CD44 variant8–10 and c-Myc are inversely expressed in gastric cancer cells. •Redox-stress enhances c-Myc expression via canonical Wnt signal. •CD44v, but not CD44 standard, suppresses redox stress-induced Wnt activation. •CD44v expression promotes both transcription and proteasome degradation of c-Myc. •Inversed expression pattern between CD44v and c-Myc is often recognized in vivo. -- Abstract: Cancer stem-like cells express high amount of CD44 variant8-10 which protects cancer cells from redox stress. We have demonstrated by immunohistochemical analysis and Western blotting, and reverse-transcription polymerase chain reaction, that CD44 variant8-10 and c-Myc tend to show the inversed expression manner in gastric cancer cells. That is attributable to the oxidative stress-induced canonical Wnt activation, and furthermore, the up-regulation of the downstream molecules, one of which is oncogenic c-Myc, is not easily to occur in CD44 variant-positive cancer cells. We have also found out that CD44v8-10 expression is associated with the turn-over of the c-Myc with the experiments using gastric cancer cell lines. This cannot be simply explained by the model of oxidative stress-induced Wnt activation. CD44v8-10-positive cancer cells are enriched at the invasive front. Tumor tissue at the invasive area is considered to be composed of heterogeneous cellular population; dormant cancer stem-like cells with CD44v8-10 {sup high}/ Fbw7 {sup high}/ c-Myc {sup low} and proliferative cancer stem-like cells with CD44v8-10 {sup high}/ Fbw7 {sup low}/ c-Myc {sup high}.

  12. 78 FR 56859 - Foreign-Trade Zone 75-Phoenix, Arizona, Authorization of Limited Production Activity, Honeywell...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-16

    ... Activity, Honeywell Aerospace, Inc. (Aircraft Engines, Systems and Components), Phoenix and Tempe, Arizona... comment (78 FR 27951-27952, 05-13-2013). Based on the FTZ Board's determination in this proceeding,...

  13. AJUBA LIM Proteins Limit Hippo Activity in Proliferating Cells by Sequestering the Hippo Core Kinase Complex in the Cytosol

    PubMed Central

    Jagannathan, Radhika; Schimizzi, Gregory V.; Zhang, Kun; Loza, Andrew J.; Yabuta, Norikazu; Nojima, Hitoshi

    2016-01-01

    The Hippo pathway controls organ growth and is implicated in cancer development. Whether and how Hippo pathway activity is limited to sustain or initiate cell growth when needed is not understood. The members of the AJUBA family of LIM proteins are negative regulators of the Hippo pathway. In mammalian epithelial cells, we found that AJUBA LIM proteins limit Hippo regulation of YAP, in proliferating cells only, by sequestering a cytosolic Hippo kinase complex in which LATS kinase is inhibited. At the plasma membranes of growth-arrested cells, AJUBA LIM proteins do not inhibit or associate with the Hippo kinase complex. The ability of AJUBA LIM proteins to inhibit YAP regulation by Hippo and to associate with the kinase complex directly correlate with their capacity to limit Hippo signaling during Drosophila wing development. AJUBA LIM proteins did not influence YAP activity in response to cell-extrinsic or cell-intrinsic mechanical signals. Thus, AJUBA LIM proteins limit Hippo pathway activity in contexts where cell proliferation is needed. PMID:27457617

  14. 210Po and 210Pb Activity Concentrations in Cigarettes Produced in Vietnam and Their Estimated Dose Contribution Due to Smoking

    NASA Astrophysics Data System (ADS)

    Tran, Thuy-Ngan N.; Le, Cong-Hao; Chau, Van-Tao

    Smoking cigarettes contributes significantly to the increase of radiation in human body because 210Po and 210Pb exist relatively high in tobacco leaves. Therefore, these two radioisotopes in eighteen of the most frequently sold cigarette brands produced in Vietnam were examined in this study. 210Po was determined by alpha spectroscopy using a passivated implanted planar silicon (PIPS) detector after a procedure including radiochemical separation and spontaneous deposition of polonium on a copper disc (the deposition efficiency of 210Po on a copper disc was approximately 94%). Sequentially, 210Pb was determined through the ingrowth of 210Po after storing the sample solutions for approximately six months. The activity concentrations of 210Po in cigarettes ranged from 13.8 to 82.6 mBq/cigarette (the mean value was 26.4 mBq/cigarette) and the activity concentrations of 210Pb in cigarettes ranged from 13.9 to 78.8 mBq/cigarette (the mean value was 25.8 mBq/cigarette). The annual committed effective dose for smokers who smoke one pack per day was also estimated to be 295.4 µSv/year (223.0 µSv/year and 72.4 µSv/year from 210Po and 210Pb, respectively). These indicated that smoking increased the risk of developing lung cancer was approximately 60 times greater for smokers than for non-smokers.

  15. Stochastic simulation of fission product activity in primary coolant due to fuel rod failures in typical PWRs under power transients

    NASA Astrophysics Data System (ADS)

    Javed Iqbal, M.; Mirza, Nasir M.; Mirza, Sikander M.

    2008-01-01

    During normal operation of PWRs, routine fuel rods failures result in release of radioactive fission products (RFPs) in the primary coolant of PWRs. In this work, a stochastic model has been developed for simulation of failure time sequences and release rates for the estimation of fission product activity in primary coolant of a typical PWR under power perturbations. In the first part, a stochastic approach is developed, based on generation of fuel failure event sequences by sampling the time dependent intensity functions. Then a three-stage model based deterministic methodology of the FPCART code has been extended to include failure sequences and random release rates in a computer code FPCART-ST, which uses state-of-the-art LEOPARD and ODMUG codes as its subroutines. The value of the 131I activity in primary coolant predicted by FPCART-ST code has been found in good agreement with the corresponding values measured at ANGRA-1 nuclear power plant. The predictions of FPCART-ST code with constant release option have also been found to have good agreement with corresponding experimental values for time dependent 135I, 135Xe and 89Kr concentrations in primary coolant measured during EDITHMOX-1 experiments.

  16. Cortical activation and inter-hemispheric sensorimotor coherence in individuals with arm dystonia due to childhood stroke

    PubMed Central

    Kukke, Sahana N.; de Campos, Ana Carolina; Damiano, Diane; Alter, Katharine E.; Patronas, Nicholas; Hallett, Mark

    2014-01-01

    Objective Dystonia is a disabling motor disorder often without effective therapies. To better understand the genesis of dystonia after childhood stroke, we analyzed electroencephalographic (EEG) recordings in this population. Methods Resting spectral power of EEG signals over bilateral sensorimotor cortices (Powrest), resting inter-hemispheric sensorimotor coherence (Cohrest), and task-related changes in power (TRPow) and coherence (TRCoh) during wrist extension were analyzed in individuals with dystonia (age 20±3 years) and healthy volunteers (age 17±5 years). Results Ipsilesional TRPow decrease was significantly lower in patients than controls during the more affected wrist task. Force deficits of the affected wrist correlated with reduced alpha TRPow decrease on the ipsilesional and not the contralesional hemisphere. Cohrest was significantly lower in patients than controls, and correlated with more severe dystonia and poorer hand function. Powrest and TRCoh were similar between groups. Conclusions The association between weakness and cortical activation during wrist extension highlights the importance of ipsilesional sensorimotor activation on function. Reduction of Cohrest in patients reflects a loss of inter-hemispheric connectivity that may result from structural changes and neuroplasticity, potentially contributing to the development of dystonia. Significance Cortical and motor dysfunction are correlated in patients with childhood stroke and may in part explain the genesis of dystonia. PMID:25499610

  17. In the Early Stages of Diabetes, Rat Retinal Mitochondria Undergo Mild Uncoupling due to UCP2 Activity

    PubMed Central

    Osorio-Paz, Ixchel; Uribe-Carvajal, Salvador; Salceda, Rocío

    2015-01-01

    In order to maintain high transmembrane ionic gradients, retinal tissues require a large amount of energy probably provided by a high rate of both, glycolysis and oxidative phosphorylation. However, little information exists on retinal mitochondrial efficiency. We analyzed the retinal mitochondrial activity in ex vivo retinas and in isolated mitochondria from normal rat retina and from short-term streptozotocin-diabetic rats. In normal ex vivo retinas, increasing glucose concentrations from 5.6mM to 30mM caused a four-fold increase in glucose accumulation and CO2 production. Retina from diabetic rats accumulated similar amounts of glucose. However, CO2 production was not as high. Isolated mitochondria from normal rat retina exhibited a resting rate of oxygen consumption of 14.6 ± 1.1 natgO (min.mg prot)-1 and a respiratory control of 4.0. Mitochondria from 7, 20 and 45 days diabetic rats increased the resting rate of oxygen consumption and the activity of the electron transport complexes; under these conditions the mitochondrial transmembrane potential decreased. In spite of this, the ATP synthesis was not modified. GDP, an UCP2 inhibitor, increased mitochondrial membrane potential and superoxide production in controls and at 45 days of diabetes. The role of UCP2 is discussed. The results suggest that at the early stage of diabetes we studied, retinal mitochondria undergo adaptations leading to maintain energetic requirements and prevent oxidative stress. PMID:25951172

  18. Estimation of landslides activities evolution due to land-use and climate change in a Pyrenean valley

    NASA Astrophysics Data System (ADS)

    Vandromme, Rosalie; Bernardie, Séverine; Houet, Thomas; Grémont, Marine; Grandjean, Gilles; Thiery, Yannick

    2016-04-01

    Global changes would have impacts worldwide, but their effects should be even more exacerbated in areas particularly vulnerable. Mountainous areas are among these vulnerable territories. Ecological systems are often at a fragile equilibrium, socio-economical activities are often climate-dependent and climate-driven natural hazards can be a major threat for human activities. In order to estimate the capacity of such mountainous valleys to face global changes (climate, but also climate- and human- induced land-use changes), it is necessary to be able to evaluate the evolution of the different threats. The present work shows a method to evaluate the influences of the evolution of both vegetation cover and climate on landslides activities over a whole valley until 2100, to propose adequate solutions for current and future forestry management. Firstly, the assessment of future land use is addressed through the construction of four prospective socio-economic scenarios up to 2050 and 2100, which are then spatially validated and modeled with LUCC models. Secondly, the climate change inputs of the project correspond to 2 scenarios of emission of greenhouse gases. The used simulations available on the portal DRIAS (http://www.drias-climat.fr) were performed with the GHG emissions scenarios (RCP: Representative concentration pathways, according to the standards defined by the GIEC) RCP 4.5 and RCP 8.5. The impact of land use and climate change is then addressed through the use of these scenarios into hazards computations. For that we use a large-scale slope stability assessment tool ALICE which combines a mechanical stability model (using finite slope analysis), a vegetation module which interfere with the first model, to take into account the effects of vegetation on the mechanical soil properties (cohesion and over-load), and an hydrogeological model. All these elements are interfaced within a GIS-based solution. In that way, future changes in temperature, precipitation and

  19. Protein phosphatase 2A regulatory subunit B56α limits phosphatase activity in the heart.

    PubMed

    Little, Sean C; Curran, Jerry; Makara, Michael A; Kline, Crystal F; Ho, Hsiang-Ting; Xu, Zhaobin; Wu, Xiangqiong; Polina, Iuliia; Musa, Hassan; Meadows, Allison M; Carnes, Cynthia A; Biesiadecki, Brandon J; Davis, Jonathan P; Weisleder, Noah; Györke, Sandor; Wehrens, Xander H; Hund, Thomas J; Mohler, Peter J

    2015-07-21

    Protein phosphatase 2A (PP2A) is a serine/threonine-selective holoenzyme composed of a catalytic, scaffolding, and regulatory subunit. In the heart, PP2A activity is requisite for cardiac excitation-contraction coupling and central in adrenergic signaling. We found that mice deficient in the PP2A regulatory subunit B56α (1 of 13 regulatory subunits) had altered PP2A signaling in the heart that was associated with changes in cardiac physiology, suggesting that the B56α regulatory subunit had an autoinhibitory role that suppressed excess PP2A activity. The increase in PP2A activity in the mice with reduced B56α expression resulted in slower heart rates and increased heart rate variability, conduction defects, and increased sensitivity of heart rate to parasympathetic agonists. Increased PP2A activity in B56α(+/-) myocytes resulted in reduced Ca(2+) waves and sparks, which was associated with decreased phosphorylation (and thus decreased activation) of the ryanodine receptor RyR2, an ion channel on intracellular membranes that is involved in Ca(2+) regulation in cardiomyocytes. In line with an autoinhibitory role for B56α, in vivo expression of B56α in the absence of altered abundance of other PP2A subunits decreased basal phosphatase activity. Consequently, in vivo expression of B56α suppressed parasympathetic regulation of heart rate and increased RyR2 phosphorylation in cardiomyocytes. These data show that an integral component of the PP2A holoenzyme has an important inhibitory role in controlling PP2A enzyme activity in the heart.

  20. Protein phosphatase 2A regulatory subunit B56α limits phosphatase activity in the heart

    PubMed Central

    Little, Sean C.; Curran, Jerry; Makara, Michael A.; Kline, Crystal F.; Ho, Hsiang-Ting; Xu, Zhaobin; Wu, Xiangqiong; Polina, Iuliia; Musa, Hassan; Meadows, Allison M.; Carnes, Cynthia A.; Biesiadecki, Brandon J.; Davis, Jonathan P.; Weisleder, Noah; Györke, Sandor; Wehrens, Xander H.; Hund, Thomas J.; Mohler, Peter J.

    2015-01-01

    Protein phosphatase 2A (PP2A) is a serine/threonine-selective holoenzyme composed of a catalytic, scaffolding, and regulatory subunit. In the heart, PP2A activity is requisite for cardiac excitation-contraction coupling and central in adrenergic signaling. We found that mice deficient in the PP2A regulatory subunit B56α (1 of 13 regulatory subunits) had altered PP2A signaling in the heart that was associated with changes in cardiac physiology, suggesting that the B56α regulatory subunit had an autoinhibitory role that suppressed excess PP2A activity. The increase in PP2A activity in the mice with reduced B56α expression resulted in slower heart rates and increased heart rate variability, conduction defects, and increased sensitivity of heart rate to parasympathetic agonists. Increased PP2A activity in B56α+/− myocytes resulted in reduced Ca2+ waves and sparks, which was associated with decreased phosphorylation (and thus decreased activation) of the ryanodine receptor RyR2, an ion channel on intracellular membranes that is involved in Ca2+ regulation in cardiomyocytes. In line with an autoinhibitory role for B56α, in vivo expression of B56α in the absence of altered abundance of other PP2A subunits decreased basal phosphatase activity. Consequently, in vivo expression of B56α suppressed parasympathetic regulation of heart rate and increased RyR2 phosphorylation in cardiomyocytes. These data show that an integral component of the PP2A holoenzyme has an important inhibitory role in controlling PP2A enzyme activity in the heart. PMID:26198358

  1. Mercury pollution on district of Dimembe river system North Sulawesi, Indonesia, due to traditional gold mining activities

    NASA Astrophysics Data System (ADS)

    Ayhuan, D.; Atteng, O.; Dondokambey, A.; Randuk, M.

    2003-05-01

    Mercury contamination caused by the amalgamation of gold in small scale gold mining is a environmental problem. Small-scale gold mining (SSGM) is common in mineral endowed developing countries. It offers an important means of livehood and has served as a safety net in times of natural calamities or economic distress. In north Sulawesi Province alone, approximately 22,000 small-scale gold miners were active in 1998, and produced an estimated 10 tonnes of gold bullion. Activities of traditional / illegal gold mining (PETI) in Dimembe of district, which is located in Minahasa Regency, North Sulawesi Province. The major environmental concern associated with PETI in mercury pollution from processing of gold-bearing ore. In both the inorganic and organic forms, mercury is one of the most toxic substances to humans. One of the environmental pollution is water pollution on district of Dimembe river system that is probably caused by the use of mercury (Hg) in processing mine ore. This mercury is used in an iron rolling vessel, wllich is called tromol. Mercury concentration at employed in this operation reaches 1 kg out of 30 kg ore. Sampling stage was conducted at Warat river, downstream Taiawaan river, Merut river and Kadumut river on late April 2002 by BAPEDALDA team together with Health Laboratory staff. Material which were sampled was water. Sampling methods carried out were bottle sample immersed about 10 cm below the water surface. The analysis method used was mercury analyzer. The analysis result show that total concentration of mercury range from 1. 69 to 25. 54 ppb. This concentration is closed to Water Quality Standard IV Class that is 0.005 mg/L (Regulation Government No. 82/2001). The result of this research indicate that the district of Dimembe river system in the gold mining area have been contaminated by mercury.

  2. DCP-LA stimulates AMPA receptor exocytosis through CaMKII activation due to PP-1 inhibition.

    PubMed

    Kanno, Takeshi; Yaguchi, Takahiro; Nagata, Tetsu; Tanaka, Akito; Nishizaki, Tomoyuki

    2009-10-01

    The linoleic acid derivative 8-[2-(2-pentyl-cyclopropylmethyl)-cyclopropyl]-octanoic acid (DCP-LA) activated Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) by inhibiting protein phosphatase-1 (PP-1). DCP-LA induced a transient huge facilitation of synaptic transmission monitored from the CA1 region of rat hippocampal slices, which was largely inhibited by the CaMKII inhibitor KN-93. DCP-LA potentiated kainate-evoked whole-cell membrane currents for Xenopus oocytes expressing alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA) receptors composed of the GluR1, GluR3, GluR1/GluR2, GluR1/GluR3, and GluR1/GluR2/GluR3 subunits, and the potentiation was significantly inhibited by KN-93. A similar potentiation was still found with mutant GluR1 (S831A) receptor lacking CaMKII phosphorylation site. The GluR1 and GluR2 subunits formed AMPA receptors in the rat hippocampus, and DCP-LA increased expression of both the subunits on the plasma membrane. The DCP-LA action was blocked by KN-93 and the exocytosis inhibitor botulinum toxin type A, but not by the endocytosis inhibitor phenylarsine oxide. DCP-LA, thus, appears to activate CaMKII through PP-1 inhibition, that stimulates AMPA receptor exocytosis to increase expression of the receptors on the plasma membrane, responsible for potentiate AMPA receptor responses and facilitation of hippocampal synaptic transmission.

  3. Loss of Subcellular Lipid Transport Due to ARV1 Deficiency Disrupts Organelle Homeostasis and Activates the Unfolded Protein Response*

    PubMed Central

    Shechtman, Caryn F.; Henneberry, Annette L.; Seimon, Tracie A.; Tinkelenberg, Arthur H.; Wilcox, Lisa J.; Lee, Eunjee; Fazlollahi, Mina; Munkacsi, Andrew B.; Bussemaker, Harmen J.; Tabas, Ira; Sturley, Stephen L.

    2011-01-01

    The ARV1-encoded protein mediates sterol transport from the endoplasmic reticulum (ER) to the plasma membrane. Yeast ARV1 mutants accumulate multiple lipids in the ER and are sensitive to pharmacological modulators of both sterol and sphingolipid metabolism. Using fluorescent and electron microscopy, we demonstrate sterol accumulation, subcellular membrane expansion, elevated lipid droplet formation, and vacuolar fragmentation in ARV1 mutants. Motif-based regression analysis of ARV1 deletion transcription profiles indicates activation of Hac1p, an integral component of the unfolded protein response (UPR). Accordingly, we show constitutive splicing of HAC1 transcripts, induction of a UPR reporter, and elevated expression of UPR targets in ARV1 mutants. IRE1, encoding the unfolded protein sensor in the ER lumen, exhibits a lethal genetic interaction with ARV1, indicating a viability requirement for the UPR in cells lacking ARV1. Surprisingly, ARV1 mutants expressing a variant of Ire1p defective in sensing unfolded proteins are viable. Moreover, these strains also exhibit constitutive HAC1 splicing that interacts with DTT-mediated perturbation of protein folding. These data suggest that a component of UPR induction in arv1Δ strains is distinct from protein misfolding. Decreased ARV1 expression in murine macrophages also results in UPR induction, particularly up-regulation of activating transcription factor-4, CHOP (C/EBP homologous protein), and apoptosis. Cholesterol loading or inhibition of cholesterol esterification further elevated CHOP expression in ARV1 knockdown cells. Thus, loss or down-regulation of ARV1 disturbs membrane and lipid homeostasis, resulting in a disruption of ER integrity, one consequence of which is induction of the UPR. PMID:21266578

  4. Loss of subcellular lipid transport due to ARV1 deficiency disrupts organelle homeostasis and activates the unfolded protein response.

    PubMed

    Shechtman, Caryn F; Henneberry, Annette L; Seimon, Tracie A; Tinkelenberg, Arthur H; Wilcox, Lisa J; Lee, Eunjee; Fazlollahi, Mina; Munkacsi, Andrew B; Bussemaker, Harmen J; Tabas, Ira; Sturley, Stephen L

    2011-04-01

    The ARV1-encoded protein mediates sterol transport from the endoplasmic reticulum (ER) to the plasma membrane. Yeast ARV1 mutants accumulate multiple lipids in the ER and are sensitive to pharmacological modulators of both sterol and sphingolipid metabolism. Using fluorescent and electron microscopy, we demonstrate sterol accumulation, subcellular membrane expansion, elevated lipid droplet formation, and vacuolar fragmentation in ARV1 mutants. Motif-based regression analysis of ARV1 deletion transcription profiles indicates activation of Hac1p, an integral component of the unfolded protein response (UPR). Accordingly, we show constitutive splicing of HAC1 transcripts, induction of a UPR reporter, and elevated expression of UPR targets in ARV1 mutants. IRE1, encoding the unfolded protein sensor in the ER lumen, exhibits a lethal genetic interaction with ARV1, indicating a viability requirement for the UPR in cells lacking ARV1. Surprisingly, ARV1 mutants expressing a variant of Ire1p defective in sensing unfolded proteins are viable. Moreover, these strains also exhibit constitutive HAC1 splicing that interacts with DTT-mediated perturbation of protein folding. These data suggest that a component of UPR induction in arv1Δ strains is distinct from protein misfolding. Decreased ARV1 expression in murine macrophages also results in UPR induction, particularly up-regulation of activating transcription factor-4, CHOP (C/EBP homologous protein), and apoptosis. Cholesterol loading or inhibition of cholesterol esterification further elevated CHOP expression in ARV1 knockdown cells. Thus, loss or down-regulation of ARV1 disturbs membrane and lipid homeostasis, resulting in a disruption of ER integrity, one consequence of which is induction of the UPR.

  5. Red colouration in apple fruit is due to the activity of the MYB transcription factor, MdMYB10.

    PubMed

    Espley, Richard V; Hellens, Roger P; Putterill, Jo; Stevenson, David E; Kutty-Amma, Sumathi; Allan, Andrew C

    2007-02-01

    Anthocyanin concentration is an important determinant of the colour of many fruits. In apple (Malus x domestica), centuries of breeding have produced numerous varieties in which levels of anthocyanin pigment vary widely and change in response to environmental and developmental stimuli. The apple fruit cortex is usually colourless, although germplasm does exist where the cortex is highly pigmented due to the accumulation of either anthocyanins or carotenoids. From studies in a diverse array of plant species, it is apparent that anthocyanin biosynthesis is controlled at the level of transcription. Here we report the transcript levels of the anthocyanin biosynthetic genes in a red-fleshed apple compared with a white-fleshed cultivar. We also describe an apple MYB transcription factor, MdMYB10, that is similar in sequence to known anthocyanin regulators in other species. We further show that this transcription factor can induce anthocyanin accumulation in both heterologous and homologous systems, generating pigmented patches in transient assays in tobacco leaves and highly pigmented apple plants following stable transformation with constitutively expressed MdMYB10. Efficient induction of anthocyanin biosynthesis in transient assays by MdMYB10 was dependent on the co-expression of two distinct bHLH proteins from apple, MdbHLH3 and MdbHLH33. The strong correlation between the expression of MdMYB10 and apple anthocyanin levels during fruit development suggests that this transcription factor is responsible for controlling anthocyanin biosynthesis in apple fruit; in the red-fleshed cultivar and in the skin of other varieties, there is an induction of MdMYB10 expression concurrent with colour formation during development. Characterization of MdMYB10 has implications for the development of new varieties through classical breeding or a biotechnological approach.

  6. Single potential analysis of cavernous electrical activity (SPACE). Experiences, limitations and perspectives.

    PubMed

    Djamilian, M H; Truss, M C; Tan, H K; Anton, P; Stief, C G; Jonas, U

    1993-01-01

    Cavernous electromyography was first introduced by Wagner and Gerstenberg in 1989. The authors developed a refined method of cavernous electromyography by means of single potential analysis in introduced this method into clinical Urology as a diagnostic procedure for the evaluation of patients presenting with erectile dysfunction. To date, our experience with single potential analysis of cavernous electrical activity (SPACE) includes more than 500 patients with erectile dysfunction of various etiologies and 92 normal control subjects. Several technical modifications and refinements have been adopted during the last 4 years. In normal control subjects, SPACE shows a regular pattern of activity with long phases of electrical silence at the usual amplification interrupted by synchronous low frequency, high amplitude potentials. In patients with disruption of the peripheral autonomic supply, typical asynchronous potentials with higher frequencies and irregular shape are observed. In complete spinal cord lesions, abnormal as well as normal electrical activity is found. In patients with a long history of insulin-dependent diabetes and presumably cavernous smooth muscle degeneration, SPACE recordings show irregular potentials with low amplitudes and slow depolarization speed. Synchronization of electrical activity is usually absent. Recent studies on patients with venous leakage show that SPACE provides independent clinical information about the cavernous smooth musculature. The recording of cavernous electrical activity is possible and reproductible. In the future, a new software for one-line date processing, storage and interpretation of SPACE signals will be available.

  7. Handgrip strength deficits best explain limitations in performing bimanual activities after stroke.

    PubMed

    Basílio, Marluce Lopes; de Faria-Fortini, Iza; Polese, Janaine Cunha; Scianni, Aline A; Faria, Christina Dcm; Teixeira-Salmela, Luci Fuscaldi

    2016-04-01

    [Purpose] To evaluate the relationships between residual strength deficits (RSD) of the upper limb muscles and the performance in bimanual activities and to determine which muscular group would best explain the performance in bimanual activities of chronic stroke individuals. [Subjects and Methods] Strength measures of handgrip, wrist extensor, elbow flexor/extensor, and shoulder flexor muscles of 107 subjects were obtained and expressed as RSD. The performance in bimanual activities was assessed by the ABILHAND questionnaire. [Results] The correlations between the RSD of handgrip and wrist extensor muscles with the ABILHAND scores were negative and moderate, whereas those with the elbow flexor/extensor and shoulder flexor muscles were negative and low. Regression analysis showed that the RSD of handgrip and wrist extensor muscles explained 38% of the variance in the ABILHAND scores. Handgrip RSD alone explained 33% of the variance. [Conclusion] The RSD of the upper limb muscles were negatively associated with the performance in bimanual activities and the RSD of handgrip muscles were the most relevant variable. It is possible that stroke subjects would benefit from interventions aiming at improving handgrip strength, when the goal is to increase the performance in bimanual activities.

  8. Factors Limiting Microbial Growth and Activity at a Proposed High-Level Nuclear Repository, Yucca Mountain, Nevada

    PubMed Central

    Kieft, T. L.; Kovacik, W. P.; Ringelberg, D. B.; White, D. C.; Haldeman, D. L.; Amy, P. S.; Hersman, L. E.

    1997-01-01

    As part of the characterization of Yucca Mountain, Nev., as a potential repository for high-level nuclear waste, volcanic tuff was analyzed for microbial abundance and activity. Tuff was collected aseptically from nine sites along a tunnel in Yucca Mountain. Microbial abundance was generally low: direct microscopic cell counts were near detection limits at all sites (3.2 x 10(sup4) to 2.0 x 10(sup5) cells g(sup-1) [dry weight]); plate counts of aerobic heterotrophs ranged from 1.0 x 10(sup1) to 3.2 x 10(sup3) CFU g(sup-1) (dry weight). Phospholipid fatty acid concentrations (0.1 to 3.7 pmol g(sup-1)) also indicated low microbial biomasses; diglyceride fatty acid concentrations, indicative of dead cells, were in a similar range (0.2 to 2.3 pmol g(sup-1)). Potential microbial activity was quantified as (sup14)CO(inf2) production in microcosms containing radiolabeled substrates (glucose, acetate, and glutamic acid); amendments with water and nutrient solutions (N and P) were used to test factors potentially limiting this activity. Similarly, the potential for microbial growth and the factors limiting growth were determined by performing plate counts before and after incubating volcanic tuff samples for 24 h under various conditions: ambient moisture, water-amended, and amended with various nutrient solutions (N, P, and organic C). A high potential for microbial activity was demonstrated by high rates of substrate mineralization (as much as 70% of added organic C in 3 weeks). Water was the major limiting factor to growth and microbial activity, while amendments with N and P resulted in little further stimulation. Organic C amendments stimulated growth more than water alone. PMID:16535670

  9. Activity induced detection limits for Earth-sized planets from radial velocity studies

    NASA Astrophysics Data System (ADS)

    Korhonen, Heidi; Gråe Jørgensen, Uffe; Andersen, Jan Marie

    2015-08-01

    The detection of exoplanets using any method is prone to confusion due to the intrinsic variability of the host star. We have recently investigated the effect of cool starspots on the detectability of exoplanets around solar-like stars and M dwarfs using the radial velocity method. Our methods use full radiative transfer, known stellar atomic and molecular lines, different surface spot configurations, and an added planetary signal. In this talk we present our methods, and apply them to studying the detectability of small planets, and especially the case of alpha Centauri B planet.

  10. Body size limits dim-light foraging activity in stingless bees (Apidae: Meliponini).

    PubMed

    Streinzer, Martin; Huber, Werner; Spaethe, Johannes

    2016-10-01

    Stingless bees constitute a species-rich tribe of tropical and subtropical eusocial Apidae that act as important pollinators for flowering plants. Many foraging tasks rely on vision, e.g. spatial orientation and detection of food sources and nest entrances. Meliponini workers are usually small, which sets limits on eye morphology and thus quality of vision. Limitations are expected both on acuity, and thus on the ability to detect objects from a distance, as well as on sensitivity, and thus on the foraging time window at dusk and dawn. In this study, we determined light intensity thresholds for flight under dim light conditions in eight stingless bee species in relation to body size in a Neotropical lowland rainforest. Species varied in body size (0.8-1.7 mm thorax-width), and we found a strong negative correlation with light intensity thresholds (0.1-79 lx). Further, we measured eye size, ocelli diameter, ommatidia number, and facet diameter. All parameters significantly correlated with body size. A disproportionately low light intensity threshold in the minute Trigonisca pipioli, together with a large eye parameter P eye suggests specific adaptations to circumvent the optical constraints imposed by the small body size. We discuss the implications of body size in bees on foraging behavior. PMID:27495990

  11. Body size limits dim-light foraging activity in stingless bees (Apidae: Meliponini).

    PubMed

    Streinzer, Martin; Huber, Werner; Spaethe, Johannes

    2016-10-01

    Stingless bees constitute a species-rich tribe of tropical and subtropical eusocial Apidae that act as important pollinators for flowering plants. Many foraging tasks rely on vision, e.g. spatial orientation and detection of food sources and nest entrances. Meliponini workers are usually small, which sets limits on eye morphology and thus quality of vision. Limitations are expected both on acuity, and thus on the ability to detect objects from a distance, as well as on sensitivity, and thus on the foraging time window at dusk and dawn. In this study, we determined light intensity thresholds for flight under dim light conditions in eight stingless bee species in relation to body size in a Neotropical lowland rainforest. Species varied in body size (0.8-1.7 mm thorax-width), and we found a strong negative correlation with light intensity thresholds (0.1-79 lx). Further, we measured eye size, ocelli diameter, ommatidia number, and facet diameter. All parameters significantly correlated with body size. A disproportionately low light intensity threshold in the minute Trigonisca pipioli, together with a large eye parameter P eye suggests specific adaptations to circumvent the optical constraints imposed by the small body size. We discuss the implications of body size in bees on foraging behavior.

  12. Extra dose due to extravehicular activity during the NASA4 mission measured by an on-board TLD system

    NASA Technical Reports Server (NTRS)

    Deme, S.; Apathy, I.; Hejja, I.; Lang, E.; Feher, I.

    1999-01-01

    A microprocessor-controlled on-board TLD system, 'Pille'96', was used during the NASA4 (1997) mission to monitor the cosmic radiation dose inside the Mir Space Station and to measure the extra dose to two astronauts in the course of their extravehicular activity (EVA). For the EVA dose measurements, CaSO4:Dy bulb dosemeters were located in specially designed pockets of the ORLAN spacesuits. During an EVA lasting 6 h, the dose ratio inside and outside Mir was measured. During the EVA, Mir crossed the South Atlantic Anomaly (SAA) three times. Taking into account the influence of these three crossings the mean EVA/internal dose rate ratio was 3.2. Internal dose mapping using CaSO4:Dy dosemeters gave mean dose rates ranging from 9.3 to 18.3 microGy h-1 at locations where the shielding effect was not the same. Evaluation results of the high temperature region of LiF dosemeters are given to estimate the mean LET.

  13. [Daptomycin: revitalizing a former drug due to the need of new active agents against grampositive multiresistant bacterias].

    PubMed

    Hernández Martí, V; Romá Sánchez, E; Salavert Lletí, M; Bosó Ribelles, V; Poveda Andrés, J L

    2007-09-01

    The development of mechanisms of resistance of many Gram-positive bacterial strains that cause complicated skin and soft tissue infections, as well as sepsis and bacteremia, has necessitated the search for new drugs that will improve treatment strategies. Daptomycin is a cyclic lipopeptide antibacterial that was launched for the treatment of complicated skin and soft tissue infections caused by Gram-positive organisms. The drug's mechanism of action is different from that of any other antibiotic. It binds to bacterial membranes and causes a rapid depolarization of membrane potential. This loss of membrane potential causes inhibition of protein, DNA and RNA synthesis, which results in bacterial cell death. The in vitro spectrum of activity of daptomycin encompasses most clinically relevant aerobic Gram-positive pathogenic bacteria. Compared to other antibiotics with a similar antibacterial spectrum, daptomycin does not cause nephrotoxicity. Taking these and other characteristics into consideration, daptomycin appears to be a good alternative to other drugs used in the treatment of complicated skin and soft tissue infections and in Gram-positive bacteremial infections.

  14. Extra dose due to extravehicular activity during the NASA4 mission measured by an on-board TLD system.

    PubMed

    Deme, S; Apathy, I; Hejja, I; Lang, E; Feher, I

    1999-01-01

    A microprocessor-controlled on-board TLD system, 'Pille'96', was used during the NASA4 (1997) mission to monitor the cosmic radiation dose inside the Mir Space Station and to measure the extra dose to two astronauts in the course of their extravehicular activity (EVA). For the EVA dose measurements, CaSO4:Dy bulb dosemeters were located in specially designed pockets of the ORLAN spacesuits. During an EVA lasting 6 h, the dose ratio inside and outside Mir was measured. During the EVA, Mir crossed the South Atlantic Anomaly (SAA) three times. Taking into account the influence of these three crossings the mean EVA/internal dose rate ratio was 3.2. Internal dose mapping using CaSO4:Dy dosemeters gave mean dose rates ranging from 9.3 to 18.3 microGy h-1 at locations where the shielding effect was not the same. Evaluation results of the high temperature region of LiF dosemeters are given to estimate the mean LET.

  15. Sediment Microbial Enzyme Activity as an Indicator of Nutrient Limitation in Great Lakes Coastal Wetlands

    EPA Science Inventory

    This study, the first to link microbial enzyme activities to regional-scale anthropogenic stressors, suggests that microbial enzyme regulation of carbon and nutrient dynamics may be sensitive indicators of nutrient dynamics in aquatic ecosystems, but further work is needed to elu...

  16. 17 CFR 401.4 - Exemption for financial institutions engaged in limited government securities dealer activities.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...; (2) The sale and subsequent repurchase and the purchase and subsequent resale of government securities pursuant to a repurchase or reverse repurchase agreement; and (3) Such other activities as have...) Section 403.5(d) of this chapter concerning certain repurchase transactions with customers. (2) A...

  17. 17 CFR 401.4 - Exemption for financial institutions engaged in limited government securities dealer activities.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...; (2) The sale and subsequent repurchase and the purchase and subsequent resale of government securities pursuant to a repurchase or reverse repurchase agreement; and (3) Such other activities as have...) Section 403.5(d) of this chapter concerning certain repurchase transactions with customers. (2) A...

  18. Microbial Enzyme Activity, Nutrient Uptake, and Nutrient Limitation in Forested Streams

    EPA Science Inventory

    We measured NH4 + and PO4 -3 uptake length (Sw), uptake velocity (Vf), uptake rate (U), biofilm enzyme activity (BEA), and channel geomorphology in streams draining forested catchments in the Northwestern (Northern California Coast Range and Cascade Mountains) and Southeastern (A...

  19. Treasury Dept. Suggests Plan to Limit Colleges' Tax Exemption for Business Activities.

    ERIC Educational Resources Information Center

    Jaschik, Scott

    1987-01-01

    Revisions of federal tax law governing the business operations of nonprofit institutions would no longer define a business activity as "related" to the organization's primary mission, and thus tax exempt, solely because it is operated for the convenience of members or students. (MSE)

  20. Earthquake response reduction of mid-story isolated system due to semi-active control using magnetorheological rotary inertia mass damper

    NASA Astrophysics Data System (ADS)

    Ito, Mai; Yoshida, Shohei; Fujitani, Hideo; Sato, Yusuke

    2015-04-01

    The dynamic characteristics of mid-story isolated buildings and seismic response reduction due to a semi-active control system were investigated using a three-lumped-mass model that simplified the sixteen story building with an isolation layer in the sixth story. A semi-active control method using a rotary inertia mass damper filled with magnetorheological fluid (MR fluid) was proposed. The damper shows both mass amplification effect due to rotational inertia and variable damping effect due to the MR fluid. The damping force is controlled by the strength of the magnetic field that is applied to the MR fluid. It is determined by using the electric current, which is calculated by the proposed semi-active control method based on the velocity of the isolation layer relative to the layer just underneath it. Real-time hybrid tests using an actual damper and simulations using a building model were conducted to check the damper model; the test results were in good agreement with the simulation results. The simulation results suggest that the response displacement of the structure above the isolation layer is significantly reduced, without increasing the response acceleration of the entire structure against near-fault pulse and long-period ground motions. The proposed semi-active control using an MR rotary inertia mass damper was confirmed to be effective for mid-story isolated buildings.

  1. Bacterial persistence is an active σS stress response to metabolic flux limitation.

    PubMed

    Radzikowski, Jakub Leszek; Vedelaar, Silke; Siegel, David; Ortega, Álvaro Dario; Schmidt, Alexander; Heinemann, Matthias

    2016-09-21

    While persisters are a health threat due to their transient antibiotic tolerance, little is known about their phenotype and what actually causes persistence. Using a new method for persister generation and high-throughput methods, we comprehensively mapped the molecular phenotype of Escherichia coli during the entry and in the state of persistence in nutrient-rich conditions. The persister proteome is characterized by σ(S)-mediated stress response and a shift to catabolism, a proteome that starved cells tried to but could not reach due to absence of a carbon and energy source. Metabolism of persisters is geared toward energy production, with depleted metabolite pools. We developed and experimentally verified a model, in which persistence is established through a system-level feedback: Strong perturbations of metabolic homeostasis cause metabolic fluxes to collapse, prohibiting adjustments toward restoring homeostasis. This vicious cycle is stabilized and modulated by high ppGpp levels, toxin/anti-toxin systems, and the σ(S)-mediated stress response. Our system-level model consistently integrates past findings with our new data, thereby providing an important basis for future research on persisters.

  2. Bacterial persistence is an active σS stress response to metabolic flux limitation.

    PubMed

    Radzikowski, Jakub Leszek; Vedelaar, Silke; Siegel, David; Ortega, Álvaro Dario; Schmidt, Alexander; Heinemann, Matthias

    2016-01-01

    While persisters are a health threat due to their transient antibiotic tolerance, little is known about their phenotype and what actually causes persistence. Using a new method for persister generation and high-throughput methods, we comprehensively mapped the molecular phenotype of Escherichia coli during the entry and in the state of persistence in nutrient-rich conditions. The persister proteome is characterized by σ(S)-mediated stress response and a shift to catabolism, a proteome that starved cells tried to but could not reach due to absence of a carbon and energy source. Metabolism of persisters is geared toward energy production, with depleted metabolite pools. We developed and experimentally verified a model, in which persistence is established through a system-level feedback: Strong perturbations of metabolic homeostasis cause metabolic fluxes to collapse, prohibiting adjustments toward restoring homeostasis. This vicious cycle is stabilized and modulated by high ppGpp levels, toxin/anti-toxin systems, and the σ(S)-mediated stress response. Our system-level model consistently integrates past findings with our new data, thereby providing an important basis for future research on persisters. PMID:27655400

  3. Multiple implantation and multiple annealing of phosphorus doped germanium to achieve n-type activation near the theoretical limit

    NASA Astrophysics Data System (ADS)

    Kim, Jeehwan; Bedell, Stephen W.; Sadana, Devendra K.

    2012-09-01

    Full activation of n-type dopant in germanium (Ge) reaching to its solid solubility has never been achieved by using ion implantation doping technique. This is because implantation of dopants always leaves defects such as vacancy and interstitials in the Ge crystal. While implantation-induced defects are electrically neutral for the most of semiconductor materials, they are electrically positive for Ge resulting in compensation of n-type dopants. In this Letter, we verified that 5 × 1019 P/cm3 is the maximum active concentration, which can be fully activated in germanium "without leaving implantation damage" per implantation/annealing cycle. The repetition of implantation and annealing of phosphorous (P) with the concentration of 5 × 1019 cm-3 leads to the activation of 1 × 1020 P/cm3 close to its solid solubility limit of 2 × 1020 P/cm3.

  4. Rate-limiting roles of the tenase complex of factors VIII and IX in platelet procoagulant activity and formation of platelet-fibrin thrombi under flow.

    PubMed

    Swieringa, Frauke; Kuijpers, Marijke J E; Lamers, Moniek M E; van der Meijden, Paola E J; Heemskerk, Johan W M

    2015-06-01

    The importance of factor Xa generation in thrombus formation has not been studied extensively so far. Here, we used mice deficient in either factor VIII or factor IX to determine the role of platelet-stimulated tenase activity in the formation of platelet-fibrin thrombi on collagen. With tissue factor present, deficiency in factor VIII or IX markedly suppressed thrombus growth, fibrin formation and platelet procoagulant activity (phosphatidylserine exposure). In either case, residual fibrin formation was eliminated in the absence of tissue factor. Effects of factor deficiencies were antagonized by supplementation of the missing coagulation factor. In wild-type thrombi generated under flow, phosphatidylserine-exposing platelets bound (activated) factor IX and factor X, whereas factor VIII preferentially co-localized at sites of von Willebrand factor binding. Furthermore, proteolytic activity of the generated activated factor X and thrombin was confined to the sites of phosphatidylserine exposure. With blood from a hemophilia A or B patient, the formation of platelet-fibrin thrombi was greatly delayed and reduced, even in the presence of high concentrations of tissue factor. A direct activated factor X inhibitor, rivaroxaban, added to human blood, suppressed both thrombin and fibrin formation. Together, these data point to a potent enforcement loop in thrombus formation due to factor X activation, subsequent thrombin and fibrin generation, causing activated factor X-mediated stimulation of platelet phosphatidylserine exposure. This implies that the factor VIII/factor IX-dependent stimulation of platelet procoagulant activity is a limiting factor for fibrin formation under flow conditions, even at high tissue factor concentrations.

  5. K-Ras Activation Induces Differential Sensitivity to Sulfur Amino Acid Limitation and Deprivation and to Oxidative and Anti-Oxidative Stress in Mouse Fibroblasts

    PubMed Central

    De Sanctis, Gaia; Spinelli, Michela; Vanoni, Marco

    2016-01-01

    Background Cancer cells have an increased demand for amino acids and require transport even of non-essential amino acids to support their increased proliferation rate. Besides their major role as protein synthesis precursors, the two proteinogenic sulfur-containing amino acids, methionine and cysteine, play specific biological functions. In humans, methionine is essential for cell growth and development and may act as a precursor for cysteine synthesis. Cysteine is a precursor for the biosynthesis of glutathione, the major scavenger for reactive oxygen species. Methodology and Principal Findings We study the effect of K-ras oncogene activation in NIH3T3 mouse fibroblasts on transport and metabolism of cysteine and methionine. We show that cysteine limitation and deprivation cause apoptotic cell death (cytotoxic effect) in both normal and K-ras-transformed fibroblasts, due to accumulation of reactive oxygen species and a decrease in reduced glutathione. Anti-oxidants glutathione and MitoTEMPO inhibit apoptosis, but only cysteine-containing glutathione partially rescues the cell growth defect induced by limiting cysteine. Methionine limitation and deprivation has a cytostatic effect on mouse fibroblasts, unaffected by glutathione. K-ras-transformed cells–but not their parental NIH3T3—are extremely sensitive to methionine limitation. This fragility correlates with decreased expression of the Slc6a15 gene—encoding the nutrient transporter SBAT1, known to exhibit a strong preference for methionine—and decreased methionine uptake. Conclusions and Significance Overall, limitation of sulfur-containing amino acids results in a more dramatic perturbation of the oxido-reductive balance in K-ras-transformed cells compared to NIH3T3 cells. Growth defects induced by cysteine limitation in mouse fibroblasts are largely–though not exclusively–due to cysteine utilization in the synthesis of glutathione, mouse fibroblasts requiring an exogenous cysteine source for

  6. Intracellular survival of Staphylococcus aureus due to alteration of cellular activity in arsenic and lead intoxicated mature Swiss albino mice.

    PubMed

    Bishayi, Biswadev; Sengupta, Mahuya

    2003-02-14

    The role of heavy metals like arsenic (As) and lead (Pb) as environmental toxicants is established. However, the exact mechanism of their effect on immunocompetent cell activity is not well known. Staphylococcus aureus is a virulent pathogen that has the ability to cause a variety of potentially life-threatening infections. The objective of our study was to demonstrate in an experimental mouse model of bacteremic S. aureus infection, bacterial clearance from blood and spleen in arsenic, lead treated and control group of mice. Bacterial density was measured in blood and spleen after 0, 24, 48 and 72 h post-infection. Our findings show a significant increase in bacterial load in blood (P<0.025 for arsenic and P<0.01 for lead) and delayed bacterial clearance by spleen in both arsenic (P<0.05) and lead (P<0.025) treated groups as compared to control, thus highlighting an immuno-compromised state following heavy metal exposure. To further elucidate immunomodulatory effects of both arsenic and lead, cell function studies were performed on splenic macrophages (M(phi)) isolated from lead and arsenic treated as well as control group of mice. Our findings show a decrease in cell adhesion property (P<0.005) of splenic M(phi)s from 2.9925+/-0.053 in control to 1.395+/-0.106 in arsenic and 0.8835+/-0.0106 in lead treated mice at 60 min. Morphologic alteration of the splenic M(phi)s showed an increase (As: P<0.05, Pb: P<0.0005) in both arsenic (6.876+/-0.3287%) and lead (16.55+/-1.051%) treated mice to control (2.649+/-1.238%) which may be responsible for the formers' reduced functional status. The chemotactic index, a measure of chemotactic migration of the macrophages toward immune serum, was 16.43+/-1.007 in control cell and was reduced (P<0.0005) to 4.19+/-0.393 in arsenic and 2.92+/-0.649 in lead treated mice at 60 min. These altered cell functions could probably explain the intracellular survival of S. aureus but such a causal relationship awaits further detailed

  7. Properties and limits of some essential oils: chemical characterisation, antimicrobial activity, interaction with antibiotics and cytotoxicity.

    PubMed

    Scazzocchio, Francesca; Garzoli, Stefania; Conti, Cinzia; Leone, Claudia; Renaioli, Clio; Pepi, Federico; Angiolella, Letizia

    2016-09-01

    Because of the emergence of multi-drug resistance bacteria and fungi, alternatives to conventional antimicrobial therapy are needed. This study aims to evaluate in vitro the antimicrobial activity of: Mirtus communis, Coriandrum sativum, Pelargonium capitatum, Cuminum cyminum, Ocimum basilicum, Citrus aurantium amara, Cymbopogon. winterianus, Cymbopogon martini, Salvia sclarea, Melaleuca alternifolia and Mentha suaveolens essential oils on bacteria and fungi, in relation to their chemical composition. The potential interaction of M. alternifolia (TTO), C. sativum (CDO) and M. suaveolens (EOMS) essential oils when used in combination with gentamicin and fluconazole has been evaluated. The results obtained showed a synergic effect on some bacteria and fungi, with FICI values ≤5. The cytotoxicity of TTO, CDO and EOMS was investigated towards HeLa cells. Only EOMS did not result cytotoxic at the active concentrations on micro-organisms. Further studies are necessary to obtain optimal ratios and dosing regimens for higher therapeutic efficacy and to decrease toxicological profiles. PMID:26395247

  8. The 1859 Solar-Terrestrial Disturbance And the Current Limits of Extreme Space Weather Activity

    NASA Astrophysics Data System (ADS)

    Cliver, E. W.; Svalgaard, L.

    2004-10-01

    It is generally appreciated that the September 1859 solar-terrestrial disturbance, the first recognized space weather event, was exceptionally large. How large and how exceptional? To answer these questions, we compiled rank order lists of the various measures of solar-induced disturbance for events from 1859 to the present. The parameters considered included: magnetic crochet amplitude, solar energetic proton fluence (McCracken et al., 2001a), Sun-Earth disturbance transit time, geomagnetic storm intensity, and low-latitude auroral extent. While the 1859 event has close rivals or superiors in each of the above categories of space weather activity, it is the only documented event of the last ˜150 years that appears at or near the top of all of the lists. Taken together, the top-ranking events in each of the disturbance categories comprise a set of benchmarks for extreme space weather activity.

  9. Treatment with polyamine oxidase inhibitor reduces microglial activation and limits vascular injury in ischemic retinopathy.

    PubMed

    Patel, C; Xu, Z; Shosha, E; Xing, J; Lucas, R; Caldwell, R W; Caldwell, R B; Narayanan, S P

    2016-09-01

    Retinal vascular injury is a major cause of vision impairment in ischemic retinopathies. Insults such as hyperoxia, oxidative stress and inflammation contribute to this pathology. Previously, we showed that hyperoxia-induced retinal neurodegeneration is associated with increased polyamine oxidation. Here, we are studying the involvement of polyamine oxidases in hyperoxia-induced injury and death of retinal vascular endothelial cells. New-born C57BL6/J mice were exposed to hyperoxia (70% O2) from postnatal day (P) 7 to 12 and were treated with the polyamine oxidase inhibitor MDL 72527 or vehicle starting at P6. Mice were sacrificed after different durations of hyperoxia and their retinas were analyzed to determine the effects on vascular injury, microglial cell activation, and inflammatory cytokine profiling. The results of this analysis showed that MDL 72527 treatment significantly reduced hyperoxia-induced retinal vascular injury and enhanced vascular sprouting as compared with the vehicle controls. These protective effects were correlated with significant decreases in microglial activation as well as levels of inflammatory cytokines and chemokines. In order to model the effects of polyamine oxidation in causing microglial activation in vitro, studies were performed using rat brain microvascular endothelial cells treated with conditioned-medium from rat retinal microglia stimulated with hydrogen peroxide. Conditioned-medium from activated microglial cultures induced cell stress signals and cell death in microvascular endothelial cells. These studies demonstrate the involvement of polyamine oxidases in hyperoxia-induced retinal vascular injury and retinal inflammation in ischemic retinopathy, through mechanisms involving cross-talk between endothelial cells and resident retinal microglia. PMID:27239699

  10. Treatment with polyamine oxidase inhibitor reduces microglial activation and limits vascular injury in ischemic retinopathy

    PubMed Central

    Patel, C.; Xu, Z.; Shosha, E.; Xing, J.; Lucas, R.; Caldwell, R.W.; Caldwell, R.B.; Narayanan, S.P.

    2016-01-01

    Retinal vascular injury is a major cause of vision impairment in ischemic retinopathies. Insults such as hyperoxia, oxidative stress and inflammation contribute to this pathology. Previously, we showed that hyperoxia-induced retinal neurodegeneration is associated with increased polyamine oxidation. Here, we are studying the involvement of polyamine oxidases in hyperoxia-induced injury and death of retinal vascular endothelial cells. Newborn C57BL6/J mice were exposed to hyperoxia (70% O2) from postnatal day (P) 7 to 12 and were treated with the polyamine oxidase inhibitor MDL 72527 or vehicle starting at P6. Mice were sacrificed after different durations of hyperoxia and their retinas were analyzed to determine the effects on vascular injury, microglial cell activation, and inflammatory cytokine profiling. The results of this analysis showed that MDL 72527 treatment significantly reduced hyperoxia-induced retinal vascular injury and enhanced vascular sprouting as compared with the vehicle controls. These protective effects were correlated with significant decreases in microglial activation as well as levels of inflammatory cytokines and chemokines. In order to model the effects of polyamine oxidation in causing microglial activation in vitro, studies were performed using rat brain microvascular endothelial cells treated with conditioned-medium from rat retinal microglia stimulated with hydrogen peroxide. Conditioned-medium from activated microglial cultures induced cell stress signals and cell death in microvascular endothelial cells. These studies demonstrate the involvement of polyamine oxidases in hyperoxia-induced retinal vascular injury and retinal inflammation in ischemic retinopathy, through mechanisms involving cross-talk between endothelial cells and resident retinal microglia. PMID:27239699

  11. A low upper limit on the subsurface rise speed of solar active regions

    PubMed Central

    Birch, Aaron C.; Schunker, Hannah; Braun, Douglas C.; Cameron, Robert; Gizon, Laurent; Löptien, Björn; Rempel, Matthias

    2016-01-01

    Magnetic field emerges at the surface of the Sun as sunspots and active regions. This process generates a poloidal magnetic field from a rising toroidal flux tube; it is a crucial but poorly understood aspect of the solar dynamo. The emergence of magnetic field is also important because it is a key driver of solar activity. We show that measurements of horizontal flows at the solar surface around emerging active regions, in combination with numerical simulations of solar magnetoconvection, can constrain the subsurface rise speed of emerging magnetic flux. The observed flows imply that the rise speed of the magnetic field is no larger than 150 m/s at a depth of 20 Mm, that is, well below the prediction of the (standard) thin flux tube model but in the range expected for convective velocities at this depth. We conclude that convective flows control the dynamics of rising flux tubes in the upper layers of the Sun and cannot be neglected in models of flux emergence. PMID:27453947

  12. A low upper limit on the subsurface rise speed of solar active regions.

    PubMed

    Birch, Aaron C; Schunker, Hannah; Braun, Douglas C; Cameron, Robert; Gizon, Laurent; Löptien, Björn; Rempel, Matthias

    2016-07-01

    Magnetic field emerges at the surface of the Sun as sunspots and active regions. This process generates a poloidal magnetic field from a rising toroidal flux tube; it is a crucial but poorly understood aspect of the solar dynamo. The emergence of magnetic field is also important because it is a key driver of solar activity. We show that measurements of horizontal flows at the solar surface around emerging active regions, in combination with numerical simulations of solar magnetoconvection, can constrain the subsurface rise speed of emerging magnetic flux. The observed flows imply that the rise speed of the magnetic field is no larger than 150 m/s at a depth of 20 Mm, that is, well below the prediction of the (standard) thin flux tube model but in the range expected for convective velocities at this depth. We conclude that convective flows control the dynamics of rising flux tubes in the upper layers of the Sun and cannot be neglected in models of flux emergence. PMID:27453947

  13. Linking nutrition and behavioural dominance: carbohydrate scarcity limits aggression and activity in Argentine ants.

    PubMed

    Grover, Crystal D; Kay, Adam D; Monson, Jessica A; Marsh, Thomas C; Holway, David A

    2007-12-01

    Predicting the outcome of competitive interactions is a fundamental goal in ecology. Ecological stoichiometry, which relates nutrient balance to ecological processes, provides a framework for identifying mechanistic links among macronutrient availability, nutritional physiology and competitive performance. Because carbohydrates serve as a principal metabolic fuel, carbohydrate scarcity may impinge upon behaviours affecting competitive dominance (e.g. aggression, activity) to a greater extent than deficiencies of protein or other nutrients used preferentially for growth. Here, we tested this prediction with a diet manipulation study involving laboratory colonies of Argentine ants (Linepithema humile), a widespread and aggressive invasive species. The availability of both sucrose and insect prey influenced brood production and worker survival after three months. However, colonies became less aggressive and less active only when deprived of sucrose (but not prey). Scarcity of sucrose (but not prey) was also associated with reduced fat mass in individual workers. These data provide the first experimental support that carbohydrate scarcity compromises aggression and activity in ants, and illustrate, in principle, how access to carbohydrate-rich resources (e.g. plant exudates, hemipteran honeydew) might influence behavioural investments that contribute to competitive performance. Such investments might be especially important for invasive ants, given their aggressiveness and tendency to interact with honeydew-producing Hemiptera.

  14. Observation and interpretation of thermal instabilities at the front face of actively cooled limiters in TORE-SUPRA

    SciTech Connect

    Guilhem, D.; Hogan, J.T.; Mitteau, R.; Phillips, V.

    1995-12-01

    In TORE-SUPRA, actively cooled modular limiters (time constant = 2 s) covered with carbon have been used to exhaust the convective heat flux continuously up to 700 kW steady state (design value) without thermal instability, i.e., 4.5 MW/m{sup 2} on average. Steady state surface temperatures in the range 600 C (with 1.45 MW of Lower Hybrid waves) were routinely obtained. However, sudden surface temperature excursions from 600 C to 1,900 C, called ``super-brilliances``, were observed during ohmic or heated plasmas, taking place locally over 20 ms, which led to a new equilibrium. This new equilibrium correspond to a local increased power flux density to the limiter as confirmed by calorimetric measurements. Shot after shot, an increasing number of independent overheated zones (up to 4) were observed on the limiter ridge, the closest location to Last Closed Flux Surface (LCFS). The power extracted by the limiter then was {approximately} 1.1 MW (6.9 MW/m{sup 2} average and 15 MW/m{sup 2} maximum). Experimental data and possible mechanisms leading to a finite increased heat flux to the limiter surface are reviewed and comparisons with modelization are made.

  15. Collaboration of local government and experts responding to increase in environmental radiation level due to the nuclear disaster: focusing on their activities and latest radiological discussion.

    PubMed

    Iimoto, T; Nunokawa, J; Fujii, H; Takashima, R; Hashimoto, M; Fukuhara, T; Yajima, T; Matsuzawa, H; Kurosawa, K; Yanagawa, Y; Someya, S

    2015-11-01

    Activities were introduced in Kashiwa city in the Tokyo metropolitan area to correspond to the elevated environmental radiation level after the disaster of the Fukushima Daiichi nuclear power plant. These were based on a strong cooperation between local governments and experts. Ambient dose rate and radioactivity of foodstuff produced inside of the city have been monitored. Representative ambient dose rates around living environments have almost already become their original levels of the pre-accident because of the decontamination activity, natural washout and effective half-lives of radioactivity. The internal annual dose due to radioactive cesium under the policy of 'Local Production for Local Consumption' is estimated as extremely low comparing the variation range due to natural radioactivity. Systematic survey around a retention basin has been started. All of these latest monitoring data would be one of the core information for the policy making as well as a cost-benefit discussion and risk communication.

  16. Collaboration of local government and experts responding to increase in environmental radiation level due to the nuclear disaster: focusing on their activities and latest radiological discussion.

    PubMed

    Iimoto, T; Nunokawa, J; Fujii, H; Takashima, R; Hashimoto, M; Fukuhara, T; Yajima, T; Matsuzawa, H; Kurosawa, K; Yanagawa, Y; Someya, S

    2015-11-01

    Activities were introduced in Kashiwa city in the Tokyo metropolitan area to correspond to the elevated environmental radiation level after the disaster of the Fukushima Daiichi nuclear power plant. These were based on a strong cooperation between local governments and experts. Ambient dose rate and radioactivity of foodstuff produced inside of the city have been monitored. Representative ambient dose rates around living environments have almost already become their original levels of the pre-accident because of the decontamination activity, natural washout and effective half-lives of radioactivity. The internal annual dose due to radioactive cesium under the policy of 'Local Production for Local Consumption' is estimated as extremely low comparing the variation range due to natural radioactivity. Systematic survey around a retention basin has been started. All of these latest monitoring data would be one of the core information for the policy making as well as a cost-benefit discussion and risk communication. PMID:25982790

  17. Preparation, In Vivo Administration, Dose-Limiting Toxicities, and Antineoplastic Activity of Cytochalasin B

    PubMed Central

    Trendowski, Matthew; Zoino, Joseph N.; Christen, Timothy D.; Acquafondata, Christopher; Fondy, Thomas P.

    2015-01-01

    An effective and inexpensive protocol for producing cytochalasins A and B is being disclosed to propose a viable method by which to examine the in vivo antineoplastic activity of these congeners in preclinical tumor-bearing mammalian models. In addition, we determine the maximum tolerated doses of cytochalasin B using multiple routes and formulations, characterize the tissue distribution of intravenous bolus cytochalasin B, and assess the in vivo antineoplastic activity of cytochalasin B in comparison in doxorubicin in Balb/c mice challenged intradermally with M109 murine lung carcinoma. We also examine the effects of cytochalasin B against several other murine neoplastic cell lines (Lewis lung, LA4, B16F10, and M5076). Finally, we examine a potential mechanism of the antimetastatic activity of cytochalasin B by observing the effects of the agent on the secretion of N-acetylglucosaminidase (GlcNACase) by B16BL6 and B16F10 murine melanomas in vitro. The results of the study can be summarized as follows: 1) Cytochalasin B can be safely administered intravenously, intraperitoneally, and subcutaneously in murine models, with the maximum tolerated dose of all routes of administration being increased by liposome encapsulation. 2) Cytochalasin B can significantly inhibit the growth of tumors in mice challenged with M109, Lewis lung, LA4, B16F10, or M5076, producing long-term survival against lung carcinomas and adenocarcinomas (M109, Lewis lung, and LA4) and B16F10 melanoma, but not M5076 sarcoma. These effects were comparable to intraperitoneally administered doxorubicin. 4) Low concentrations of cytochalasin B inhibit the secretion of GlcNACase, indicating that cytochalasin B may inhibit metastatic progression by mechanisms not directly associated with its influence on cell adhesion and motility. PMID:26310377

  18. Limitations of Endovascular Treatment with Stent-Grafts for Active Mycotic Thoracic Aortic Aneurysm

    SciTech Connect

    Ishida, Masaki; Kato, Noriyuki; Hirano, Tadanori; Shimono, Takatsugu; Yasuda, Fuyuhiko; Tanaka, Kuniyoshi; Yada, Isao; Takeda, Kan

    2002-06-15

    An 81-year-old woman with ruptured mycotic thoracic aortic aneurysm was treated with endovascular placement of stent-grafts fabricated from expanded polytetrafluoroethylene and Z-stents. Although exclusion of the aneurysm was achieved at the end of the procedure, a type I endoleak developed on the following day.Despite emergent surgical resection of the aneurysm and extra-anatomical reconstruction, the patient died 2 days later. Stent-graft repair may not be a suitable method for the treatment of ruptured mycotic aneurysm in the presence of active infection.

  19. Phase behavior and critical activated dynamics of limited-valence DNA nanostars.

    PubMed

    Biffi, Silvia; Cerbino, Roberto; Bomboi, Francesca; Paraboschi, Elvezia Maria; Asselta, Rosanna; Sciortino, Francesco; Bellini, Tommaso

    2013-09-24

    Colloidal particles with directional interactions are key in the realization of new colloidal materials with possibly unconventional phase behaviors. Here we exploit DNA self-assembly to produce bulk quantities of "DNA stars" with three or four sticky terminals, mimicking molecules with controlled limited valence. Solutions of such molecules exhibit a consolution curve with an upper critical point, whose temperature and concentration decrease with the valence. Upon approaching the critical point from high temperature, the intensity of the scattered light diverges with a power law, whereas the intensity time autocorrelation functions show a surprising two-step relaxation, somehow reminiscent of glassy materials. The slow relaxation time exhibits an Arrhenius behavior with no signs of criticality, demonstrating a unique scenario where the critical slowing down of the concentration fluctuations is subordinate to the large lifetime of the DNA bonds, with relevant analogies to critical dynamics in polymer solutions. The combination of equilibrium and dynamic behavior of DNA nanostars demonstrates the potential of DNA molecules in diversifying the pathways toward collective properties and self-assembled materials, beyond the range of phenomena accessible with ordinary molecular fluids.

  20. Profound desensitization by ambient GABA limits activation of δ-containing GABAA receptors during spillover.

    PubMed

    Bright, Damian P; Renzi, Massimiliano; Bartram, Julian; McGee, Thomas P; MacKenzie, Georgina; Hosie, Alastair M; Farrant, Mark; Brickley, Stephen G

    2011-01-12

    High-affinity extrasynaptic GABA(A) receptors (GABA(A)Rs) are a prominent feature of cerebellar granule neurons and thalamic relay neurons. In both cell types, the presence of synaptic glomeruli would be expected to promote activation of these GABA(A)Rs, contributing to phasic spillover-mediated currents and tonic inhibition. However, the precise role of different receptor subtypes in these two phenomena is unclear. To address this question, we made recordings from neurons in acute brain slices from mice, and from tsA201 cells expressing recombinant GABA(A)Rs. We found that δ subunit-containing GABA(A)Rs of both cerebellar granule neurons and thalamic relay neurons of the lateral geniculate nucleus contributed to tonic conductance caused by ambient GABA but not to spillover-mediated currents. In the presence of a low "ambient" GABA concentration, recombinant "extrasynaptic" δ subunit-containing GABA(A)Rs exhibited profound desensitization, rendering them insensitive to brief synaptic- or spillover-like GABA transients. Together, our results demonstrate that phasic spillover and tonic inhibition reflect the activation of distinct receptor populations.

  1. Quantitative detection of RT activity by PERT assay: feasibility and limits to a standardized screening assay for human vaccines.

    PubMed

    André, M; Morgeaux, S; Fuchs, F

    2000-06-01

    The detection of adventitious retroviruses has always been critical for assessing the safety concerns associated with viral vaccines. Assays for the enzymatic activity of reverse transcriptase (RT) are used as general methods for the detection of both known and unknown retroviruses. Several studies using newly-developed ultrasensitive PCR-based RT assays reported RT activity in viral vaccines grown in chicken cells. Here, we have assessed the performances of such a PCR-based RT assay--PERT assay--for the quantitative detection of RT activity in vaccines. Sensitivity, linearity and reproducibility of the method were studied on purified RT and viral vaccines treated to release RT from potentially contaminant retroviruses. The level of RT activity detected in chicken cell-derived vaccines was higher for live attenuated vaccines compared to inactivated ones. Contrary to other studies, RT activity was found in some mammalian cell-derived vaccines. AZT-TP sensitivity of RT activities detected in these vaccines and discrimination between retroviral and RT-like activities was further investigated. Feasibility and limits of PERT assay as a broad-spectrum retroviruses detection method in vaccines are discussed.

  2. Fall armyworm sensitivity to flavone: Limited role of constitutive and induced detoxifying enzyme activity.

    PubMed

    Wheeler, G S; Slansky, F; Yu, S J

    1993-04-01

    We used inhibition and induction of detoxifying enzymes to determine whether these enzymes allow a generalist species (Spodoptera frugiperda; fall armyworms) to cope with ingestion of the flavonoid, flavone. Flavone induces polysubstrate monooxygenases (PSMO), general esterases (GE), and glutathioneS-transferases (GST) inS. frugiperda, yet this species is affected deleteriously by low dietary concentrations of this allelochemical. First, in a series of experiments, larvae were fed artificial diets containing increasing concentrations of flavone, either alone or with known inhibitors of either PSMO, GE, or GST enzymes. In an additional treatment, flavone and inhibitors of all three enzyme systems were administered in diets simultaneously. PSMO and GE activities were reduced in vivo by their respective inhibitors, whereas that of GST was induced or unchanged. Significant synergism of flavone's growth-reducing activity occurred at the highest concentration tested (0.125% fresh mass, fm) when the PSMO inhibitor, piperonyl butoxide, or the GST inhibitor, diethyl maleate, was added to the diet, and at 0.08% fm flavone, when combined with the GE inhibitor, tri-tolyl phosphate. In many cases, however, the additive effect (i.e., reduction in growth owing to flavone alone + inhibitor alone) was greater than the synergistic effect, and no synergism occurred in the treatment with the three inhibitors combined. In the second approach, caterpillars were preexposed to a concentration of flavone (0.02% fm) that induced these enzymes ca. 1.5- to 2.5-fold, prior to switching larvae to a diet containing a higher (growth-reducing) flavone concentration (0.125% fm). The relative growth rates (RGR) of induced larvae were significantly greater (14%) than those of the uninduced larvae on the 0.125% fm flavone diet. Additionally, in two of the three experiments, relative consumption rate (RCR) was significantly greater (7-24%) in induced compared with uninduced larvae. The variable

  3. Nerve growth factor-mediated inhibition of apoptosis post-caspase activation is due to removal of active caspase-3 in a lysosome-dependent manner

    PubMed Central

    Mnich, K; Carleton, L A; Kavanagh, E T; Doyle, K M; Samali, A; Gorman, A M

    2014-01-01

    Nerve growth factor (NGF) is well characterised as an important pro-survival factor in neuronal cells that can inhibit apoptotic cell death upstream of mitochondrial outer membrane permeabilisation. Here we addressed the question of whether NGF can also protect against apoptosis downstream of caspase activation. NGF treatment promoted a rapid reduction in the level of the p17 subunit of active caspase-3 in PC12 cells that had been induced to undergo apoptosis by various cytotoxins. The mechanism involved TrkA-dependent activation of extracellular signal-regulated kinase (ERK1/2) but not phosphatidylinositol 3-kinase (PI3K)/Akt, and de novo protein synthesis. Involvement of inhibitor of apoptosis proteins (IAPs) and proteasomal degradation were ruled out. In contrast, inhibition of lysosome function using chloroquine and concanamycin A reversed NGF-induced removal of p17. Moreover, in NGF-treated cells, active caspases were found to be localised to lysosomes. The involvement of macroautophagy and chaperone-mediated autophagy were ruled out. Taken together, these findings suggest an anti-apoptotic mechanism by which NGF induces removal of active caspase-3 in a lysosome-dependent manner. PMID:24787014

  4. Summer declines in activity and body temperature offer polar bears limited energy savings

    USGS Publications Warehouse

    Whiteman, J.P.; Harlow, H.J.; Durner, George M.; Anderson-Sprecher, R.; Albeke, Shannon E.; Regehr, Eric V.; Amstrup, Steven C.; Ben-David, M.

    2015-01-01

    Polar bears (Ursus maritimus) summer on the sea ice or, where it melts, on shore. Although the physiology of “ice” bears in summer is unknown, “shore” bears purportedly minimize energy losses by entering a hibernation-like state when deprived of food. Such a strategy could partially compensate for the loss of on-ice foraging opportunities caused by climate change. However, here we report gradual, moderate declines in activity and body temperature of both shore and ice bears in summer, resembling energy expenditures typical of fasting, nonhibernating mammals. Also, we found that to avoid unsustainable heat loss while swimming, bears employed unusual heterothermy of the body core. Thus, although well adapted to seasonal ice melt, polar bears appear susceptible to deleterious declines in body condition during the lengthening period of summer food deprivation.

  5. Animal physiology. Summer declines in activity and body temperature offer polar bears limited energy savings.

    PubMed

    Whiteman, J P; Harlow, H J; Durner, G M; Anderson-Sprecher, R; Albeke, S E; Regehr, E V; Amstrup, S C; Ben-David, M

    2015-07-17

    Polar bears (Ursus maritimus) summer on the sea ice or, where it melts, on shore. Although the physiology of "ice" bears in summer is unknown, "shore" bears purportedly minimize energy losses by entering a hibernation-like state when deprived of food. Such a strategy could partially compensate for the loss of on-ice foraging opportunities caused by climate change. However, here we report gradual, moderate declines in activity and body temperature of both shore and ice bears in summer, resembling energy expenditures typical of fasting, nonhibernating mammals. Also, we found that to avoid unsustainable heat loss while swimming, bears employed unusual heterothermy of the body core. Thus, although well adapted to seasonal ice melt, polar bears appear susceptible to deleterious declines in body condition during the lengthening period of summer food deprivation.

  6. Rph1 mediates the nutrient-limitation signaling pathway leading to transcriptional activation of autophagy.

    PubMed

    Bernard, Amélie; Klionsky, Daniel J

    2015-04-01

    To maintain proper cellular homeostasis, the magnitude of autophagy activity has to be finely tuned in response to environmental changes. Many aspects of autophagy regulation have been extensively studied: pathways integrating signals through the master regulators TORC1 and PKA lead to multiple post-translational modifications affecting the functions, protein-protein interactions, and localization of Atg proteins. The expression of several ATG genes increases sharply upon autophagy induction conditions, and defects in ATG gene expression are associated with various diseases, pointing to the importance of transcriptional regulation of autophagy. Yet, how changes in ATG gene expression affect the rate of autophagy is not well characterized, and transcriptional regulators of the autophagy pathway remain largely unknown. To identify such regulators, we analyzed the expression of several ATG genes in a library of DNA-binding protein mutants. This led to the identification of Rph1 as a master transcriptional regulator of autophagy.

  7. Animal physiology. Summer declines in activity and body temperature offer polar bears limited energy savings.

    PubMed

    Whiteman, J P; Harlow, H J; Durner, G M; Anderson-Sprecher, R; Albeke, S E; Regehr, E V; Amstrup, S C; Ben-David, M

    2015-07-17

    Polar bears (Ursus maritimus) summer on the sea ice or, where it melts, on shore. Although the physiology of "ice" bears in summer is unknown, "shore" bears purportedly minimize energy losses by entering a hibernation-like state when deprived of food. Such a strategy could partially compensate for the loss of on-ice foraging opportunities caused by climate change. However, here we report gradual, moderate declines in activity and body temperature of both shore and ice bears in summer, resembling energy expenditures typical of fasting, nonhibernating mammals. Also, we found that to avoid unsustainable heat loss while swimming, bears employed unusual heterothermy of the body core. Thus, although well adapted to seasonal ice melt, polar bears appear susceptible to deleterious declines in body condition during the lengthening period of summer food deprivation. PMID:26185248

  8. Extravehicular activities limitations study. Volume 2: Establishment of physiological and performance criteria for EVA gloves

    NASA Technical Reports Server (NTRS)

    Ohara, John M.; Briganti, Michael; Cleland, John; Winfield, Dan

    1988-01-01

    One of the major probelms faced in Extravehicular Activity (EVA) glove development has been the absence of concise and reliable methods to measure the effects of EVA gloves on human hand capabilities. This report describes the development of a standardized set of tests designed to assess EVA-gloved hand capabilities in six measurement domains: Range of Motion, Strength, Tactile Perception, Dexterity, Fatigue, and Comfort. Based on an assessment of general human hand functioning and EVA task requirements several tests within each measurement domain were developed to provide a comprehensive evaluation. All tests were designed to be conducted in a glove box with the bare hand as a baseline and the EVA glove at operating pressure. A test program was conducted to evaluate the tests using a representative EVA glove. Eleven test subjects participated in a repeated-measures design. The report presents the results of the tests in each capability domain.

  9. Advantages and limitations of different p62-based assays for estimating autophagic activity in Drosophila.

    PubMed

    Pircs, Karolina; Nagy, Peter; Varga, Agnes; Venkei, Zsolt; Erdi, Balazs; Hegedus, Krisztina; Juhasz, Gabor

    2012-01-01

    Levels of the selective autophagy substrate p62 have been established in recent years as a specific readout for basal autophagic activity. Here we compared different experimental approaches for using this assay in Drosophila larvae. Similar to the more commonly used western blots, quantifying p62 dots in immunostained fat body cells of L3 stage larvae detected a strong accumulation of endogenous p62 aggregates in null mutants for Atg genes and S6K. Importantly, genes whose mutation or silencing results in early stage lethality can only be analyzed by microscopy using clonal analysis. The loss of numerous general housekeeping genes show a phenotype in large-scale screens including autophagy, and the p62 assay was potentially suitable for distinguishing bona fide autophagy regulators from silencing of a DNA polymerase subunit or a ribosomal gene that likely has a non-specific effect on autophagy. p62 accumulation upon RNAi silencing of known autophagy regulators was dependent on the duration of the knockdown effect, unlike in the case of starvation-induced autophagy. The endogenous p62 assay was more sensitive than a constitutively overexpressed p62-GFP reporter, which showed self-aggregation and large-scale accumulation even in control cells. We recommend western blots for following the conversion of overexpressed p62-GFP reporters to estimate autophagic activity if sample collection from mutant larvae or adults is possible. In addition, we also showed that overexpressed p62 or Atg8 reporters can strongly influence the phenotypes of each other, potentially giving rise to false or contradicting results. Overexpressed p62 aggregates also incorporated Atg8 reporter molecules that might lead to a wrong conclusion of strongly enhanced autophagy, whereas expression of an Atg8 reporter transgene rescued the inhibitory effect of a dominant-negative Atg4 mutant on basal and starvation-induced autophagy. PMID:22952930

  10. Internet-delivered lifestyle physical activity intervention: limited inflammation and antioxidant capacity efficacy in overweight adults.

    PubMed

    Smith, Derek T; Carr, Lucas J; Dorozynski, Chris; Gomashe, Chirag

    2009-01-01

    Overweight and physical inactivity are associated with elevated reactive oxygen species and chronic low-grade inflammation. Exercise training studies have measured changes in systemic inflammatory and oxidative/antioxidative biomarkers but predominantly at moderate-high intensities. Few low-intensity, lifestyle-based physical activity (PA) studies have been conducted. The purpose of this study was to determine whether improvements in lifestyle-oriented PA resulting from a 16-wk Internet-delivered PA program [Active Living Every Day-Internet (ALED-I)] elicit cardioprotective improvements in measures of inflammation, oxidation, or antioxidant enzyme capacity. Forty-one men and women (age 23-62 yr) were randomized to either the ALED-I intervention [n = 19; age = 40.4 +/- 1.9 yr; body mass index (BMI) = 31.4 +/- 1.1 kg/m(2)] or a delayed intent-to-treat control condition (n = 22; age = 46.6 +/- 1.3 yr; BMI = 31.0 +/- 0.7 kg/m(2)). TNF-alpha, C-reactive protein, myeloperoxidase, superoxide dismutase, catalase, total antioxidative capacity, change in PA, and other cardiometabolic disease risk factors were measured at baseline and postintervention. The ALED-I group increased PA and decreased central adiposity without changes in the control group. There was no change in the control group for any inflammation, oxidation, or antioxidant biomarkers. TNF-alpha decreased (P = 0.01) in the intervention group but was not statistically different from the control group. In conclusion, modest improvements in daily low-intensity ambulatory PA as a result of an Internet-delivered lifestyle PA intervention may be cardioprotective in sedentary and overweight adults through reductions in central adiposity and inflammation. However, the absence of favorable changes in other inflammation, oxidation, and antioxidant biomarkers highlights the need for further attention to the dose response of lifestyle-structured PA promotion strategies for health maintenance/improvement.

  11. A NEW UNDERSTANDING OF THE EUROPA ATMOSPHERE AND LIMITS ON GEOPHYSICAL ACTIVITY

    SciTech Connect

    Shemansky, D. E.; Liu, X.; Yoshii, J.; Yung, Y. L.; Hansen, C. J.; Hendrix, A. R.; Esposito, L. W.

    2014-12-20

    Deep extreme ultraviolet spectrograph exposures of the plasma sheet at the orbit of Europa, obtained in 2001 using the Cassini Ultraviolet Imaging Spectrograph experiment, have been analyzed to determine the state of the gas. The results are in basic agreement with earlier results, in particular with Voyager encounter measurements of electron density and temperature. Mass loading rates and lack of detectable neutrals in the plasma sheet, however, are in conflict with earlier determinations of atmospheric composition and density at Europa. A substantial fraction of the plasma species at the Europa orbit are long-lived sulfur ions originating at Io, with ∼25% derived from Europa. During the outward radial diffusion process to the Europa orbit, heat deposition forces a significant rise in plasma electron temperature and latitudinal size accompanied with conversion to higher order ions, a clear indication that mass loading from Europa is very low. Analysis of far ultraviolet spectra from exposures on Europa leads to the conclusion that earlier reported atmospheric measurements have been misinterpreted. The results in the present work are also in conflict with a report that energetic neutral particles imaged by the Cassini ion and neutral camera experiment originate at the Europa orbit. An interpretation of persistent energetic proton pitch angle distributions near the Europa orbit as an effect of a significant population of neutral gas is also in conflict with the results of the present work. The general conclusion drawn here is that Europa is geophysically far less active than inferred in previous research, with mass loading of the plasma sheet ≤4.5 × 10{sup 25} atoms s{sup –1} two orders of magnitude below earlier published calculations. Temporal variability in the region joining the Io and Europa orbits, based on the accumulated evidence, is forced by the response of the system to geophysical activity at Io. No evidence for the direct injection of H{sub 2}O

  12. Limitations of the potentiometric titration technique in determining the proton active site density of goethite surfaces

    NASA Astrophysics Data System (ADS)

    Lützenkirchen, Johannes; Boily, Jean-François; Lövgren, Lars; Sjöberg, Staffan

    2002-10-01

    Density of proton active surface sites at mineral surfaces is a property of fundamental importance in equilibrium modeling of surface complexation reactions. In this article, methods for an experimental determination of these sites at the surface of α-FeOOH (goethite) are explored. It is shown that previously obtained saturation data of goethite with respect to protons do not yield a site density that can be considered as an intrinsic sorbent property: the results are below crystallographically expected values and values for different ionic media in terms of composition and concentration yield different numbers - for example, chloride would yield higher values than nitrate at the same concentration, and higher electrolyte concentration would favor higher apparent maxima. Although site saturation might be explained by electrostatic repulsion, which is more efficient at high electrolyte concentration or for certain ions, further independent experimental results show that no saturation occurs on goethite down to ph ≡ -log[H +] = 2.2 and possibly to ph = 1.0 in 0.6 M NaCl. For those very low pH values, the experimental charging curve was obtained by coulometric back titration (using the Gran plot) or titrations with tris (hydroxymethyl)-aminomethane of the supernatant of acidified goethite suspension. These experimental data are to our knowledge the first high quality data at such low pHs. However, small errors in the determination of proton concentrations (1%) are shown to strongly affect the shape of the charging curve for ph < 2. Furthermore, goethite dissolution (proton consumption and iron reduction in coulometric titrations) and liquid junction effects interfere at low ph, hampering the straightforward application of coulometric Gran titrations over the whole pH range. From these experiments, it can nonetheless be ascertained that a minimum of 2.5 protons/nm 2 can be adsorbed at the goethite surface from the point of zero charge (ph 9.4) to pH 0.9. Although

  13. A New Understanding of the Europa Atmosphere and Limits on Geophysical Activity

    NASA Astrophysics Data System (ADS)

    Shemansky, D. E.; Yung, Y. L.; Liu, X.; Yoshii, J.; Hansen, C. J.; Hendrix, A. R.; Esposito, L. W.

    2014-12-01

    Deep extreme ultraviolet spectrograph exposures of the plasma sheet at the orbit of Europa, obtained in 2001 using the Cassini Ultraviolet Imaging Spectrograph experiment, have been analyzed to determine the state of the gas. The results are in basic agreement with earlier results, in particular with Voyager encounter measurements of electron density and temperature. Mass loading rates and lack of detectable neutrals in the plasma sheet, however, are in conflict with earlier determinations of atmospheric composition and density at Europa. A substantial fraction of the plasma species at the Europa orbit are long-lived sulfur ions originating at Io, with ~25% derived from Europa. During the outward radial diffusion process to the Europa orbit, heat deposition forces a significant rise in plasma electron temperature and latitudinal size accompanied with conversion to higher order ions, a clear indication that mass loading from Europa is very low. Analysis of far ultraviolet spectra from exposures on Europa leads to the conclusion that earlier reported atmospheric measurements have been misinterpreted. The results in the present work are also in conflict with a report that energetic neutral particles imaged by the Cassini ion and neutral camera experiment originate at the Europa orbit. An interpretation of persistent energetic proton pitch angle distributions near the Europa orbit as an effect of a significant population of neutral gas is also in conflict with the results of the present work. The general conclusion drawn here is that Europa is geophysically far less active than inferred in previous research, with mass loading of the plasma sheet <=4.5 × 1025 atoms s-1 two orders of magnitude below earlier published calculations. Temporal variability in the region joining the Io and Europa orbits, based on the accumulated evidence, is forced by the response of the system to geophysical activity at Io. No evidence for the direct injection of H2O into the Europa

  14. Intracellular growth inhibition of Histoplasma capsulatum induced in murine macrophages by recombinant gamma interferon is not due to a limitation of the supply of methionine or cysteine to the fungus.

    PubMed Central

    Wu-Hsieh, B A; Howard, D H

    1992-01-01

    Recombinant murine gamma interferon (rMuIFN-gamma) stimulates mouse peritoneal macrophages to inhibit the intracellular growth of the zoopathogenic fungus Histoplasma capsulatum. In some systems, the inhibition of growth of an intracellular parasite by rIFN-gamma has been related to nutritional constraints induced in the host cells by the lymphokine. Such an explanation might apply to H. capsulatum because the fungus is a functional methionine-cysteine (Met-Cys) auxotroph at 37 degrees C; its sulfite reductase is repressed at that temperature. For this reason, we set about to examine whether or not the antihistoplasma state induced in rMuIFN-gamma is due to a restriction in the availability of Met-Cys. Omission of Met-Cys from the medium in which macrophages were cultivated prevented H. capsulatum from growing within them. Addition of Met or Cys to the macrophage cultures did not antagonize the inhibitory effect induced in the cells by rMuIFN-gamma. Thus, there was no evidence from our work that rMuIFN-gamma evokes the antihistoplasma effect in mouse peritoneal macrophages by limiting the supply of Met-Cys to the fungus. PMID:1730506

  15. Limits of active laser triangulation as an instrument for high precision plant imaging.

    PubMed

    Paulus, Stefan; Eichert, Thomas; Goldbach, Heiner E; Kuhlmann, Heiner

    2014-02-05

    Laser scanning is a non-invasive method for collecting and parameterizing 3D data of well reflecting objects. These systems have been used for 3D imaging of plant growth and structure analysis. A prerequisite is that the recorded signals originate from the true plant surface. In this paper we studied the effects of species, leaf chlorophyll content and sensor settings on the suitability and accuracy of a commercial 660 nm active laser triangulation scanning device. We found that surface images of Ficus benjamina leaves were inaccurate at low chlorophyll concentrations and a long sensor exposure time. Imaging of the rough waxy leaf surface of leek (Allium porrum) was possible using very low exposure times, whereas at higher exposure times penetration and multiple refraction prevented the correct imaging of the surface. A comparison of scans with varying exposure time enabled the target-oriented analysis to identify chlorotic, necrotic and healthy leaf areas or mildew infestations. We found plant properties and sensor settings to have a strong influence on the accuracy of measurements. These interactions have to be further elucidated before laser imaging of plants is possible with the high accuracy required for e.g., the observation of plant growth or reactions to water stress.

  16. The genome of the square archaeon Haloquadratum walsbyi : life at the limits of water activity

    PubMed Central

    Bolhuis, Henk; Palm, Peter; Wende, Andy; Falb, Michaela; Rampp, Markus; Rodriguez-Valera, Francisco; Pfeiffer, Friedhelm; Oesterhelt, Dieter

    2006-01-01

    Background The square halophilic archaeon Haloquadratum walsbyi dominates NaCl-saturated and MgCl2 enriched aquatic ecosystems, which imposes a serious desiccation stress, caused by the extremely low water activity. The genome sequence was analyzed and physiological and physical experiments were carried out in order to reveal how H. walsbyi has specialized into its narrow and hostile ecological niche and found ways to cope with the desiccation stress. Results A rich repertoire of proteins involved in phosphate metabolism, phototrophic growth and extracellular protective polymers, including the largest archaeal protein (9159 amino acids), a homolog to eukaryotic mucins, are amongst the most outstanding features. A relatively low GC content (47.9%), 15–20% less than in other halophilic archaea, and one of the lowest coding densities (76.5%) known for prokaryotes might be an indication for the specialization in its unique environment Conclusion Although no direct genetic indication was found that can explain how this peculiar organism retains its square shape, the genome revealed several unique adaptive traits that allow this organism to thrive in its specific and extreme niche. PMID:16820047

  17. Escherichia coli and Candida albicans Induced Macrophage Extracellular Trap-Like Structures with Limited Microbicidal Activity

    PubMed Central

    Liao, Chengshui; Liu, Xiaolei; Du, Jing; Shi, Haining; Wang, Xuelin; Bai, Xue; Peng, Peng; Yu, Lu; Wang, Feng; Zhao, Ying; Liu, Mingyuan

    2014-01-01

    The formation of extracellular traps (ETs) has recently been recognized as a novel defense mechanism in several types of innate immune cells. It has been suggested that these structures are toxic to microbes and contribute significantly to killing several pathogens. However, the role of ETs formed by macrophages (METs) in defense against microbes remains little known. In this study, we demonstrated that a subset of murine J774A.1 macrophage cell line (8% to 17%) and peritoneal macrophages (8.5% to 15%) form METs-like structures (METs-LS) in response to Escherichia coli and Candida albicans challenge. We found only a portion of murine METs-LS, which are released by dying macrophages, showed detectable killing effects on trapped E. coli but not C. albicans. Fluorescence and scanning electron microscopy analyses revealed that, in vitro, both microorganisms were entrapped in J774A.1 METs-LS composed of DNA and microbicidal proteins such as histone, myeloperoxidase and lysozyme. DNA components of both nucleus and mitochondrion origins were detectable in these structures. Additionally, METs-LS formation occurred independently of ROS produced by NADPH oxidase, and this process did not result in cell lysis. In summary, our results emphasized that microbes induced METs-LS in murine macrophage cells and that the microbicidal activity of these METs-LS differs greatly. We propose the function of METs-LS is to contain invading microbes at the infection site, thereby preventing the systemic diffusion of them, rather than significantly killing them. PMID:24587206

  18. OBSERVATIONAL LIMITS ON TYPE 1 ACTIVE GALACTIC NUCLEUS ACCRETION RATE IN COSMOS

    SciTech Connect

    Trump, Jonathan R.; Impey, Chris D.; Gabor, Jared; Kelly, Brandon C.; Elvis, Martin; Hao Heng; Huchra, John P.; Merloni, Andrea; Bongiorno, Angela; Brusa, Marcella; Cappelluti, Nico; McCarthy, Patrick J.; Koekemoer, Anton; Nagao, Tohru; Salvato, Mara; Scoville, Nick Z.

    2009-07-20

    We present black hole masses and accretion rates for 182 Type 1 active galactic nuclei (AGNs) in COSMOS. We estimate masses using the scaling relations for the broad H {beta}, Mg II, and C IV emission lines in the redshift ranges 0.16 < z < 0.88, 1 < z < 2.4, and 2.7 < z < 4.9. We estimate the accretion rate using an Eddington ratio L{sub I}/L{sub Edd} estimated from optical and X-ray data. We find that very few Type 1 AGNs accrete below L{sub I} /L{sub Edd} {approx} 0.01, despite simulations of synthetic spectra which show that the survey is sensitive to such Type 1 AGNs. At lower accretion rates the broad-line region may become obscured, diluted, or nonexistent. We find evidence that Type 1 AGNs at higher accretion rates have higher optical luminosities, as more of their emission comes from the cool (optical) accretion disk with respect to shorter wavelengths. We measure a larger range in accretion rate than previous works, suggesting that COSMOS is more efficient at finding low accretion rate Type 1 AGNs. However, the measured range in accretion rate is still comparable to the intrinsic scatter from the scaling relations, suggesting that Type 1 AGNs accrete at a narrow range of Eddington ratio, with L{sub I} /L{sub Edd} {approx} 0.1.

  19. Active Breathing Control for Hodgkin's Disease in Childhood and Adolescence: Feasibility, Advantages, and Limits

    SciTech Connect

    Claude, Line . E-mail: claude@lyon.fnclcc.fr; Malet, Claude Phys.; Pommier, Pascal; Thiesse, Philippe; Chabaud, Sylvie; Carrie, Christian

    2007-04-01

    Purpose: The challenge in early Hodgkin's disease (HD) in children is to maintain good survival rates while sparing organs at risk. This study assesses the feasibility of active breathing control (ABC) in children, and compares normal tissue irradiation with and without ABC. Methods and Materials: Between May 2003 and June 2004, seven children with HD with mediastinal involvement, median age 15, were treated by chemotherapy and involved-field radiation therapy. A free-breathing computed tomography simulation scan and one additional scan during deep inspiration using ABC were performed. A comparison between planning treatment with clinical target volume including supraclavicular regions, mediastinum, and hila was performed, both in free breathing and using ABC. Results: For a prescription of 36 Gy, pulmonary dose-volume histograms revealed a mean reduction in lung volume irradiated at more than 20 Gy (V20) and 30 Gy (V30) of 25% and 26%, respectively, using ABC (p = 0.016). The mean volume of heart irradiated at 30 Gy or more decreased from 15% to 12% (nonsignificant). The mean dose delivered to breasts in girls was small in both situations (less than 2 Gy) and stable with or without ABC. Considering axillary irradiation, the mean dose delivered to breasts remained low (<9 Gy), without significant difference using ABC or not. The mean radiation dose delivered to thyroid was stable using ABC or not. Conclusions: Using ABC is feasible in childhood. The use of ABC decreases normal lung tissue irradiation. Concerning heart irradiation, a minimal gain is also shown. No significant change has been demonstrated concerning breast and thyroid irradiation.

  20. Rheological signatures in limit cycle behaviour of dilute, active, polar liquid crystalline polymers in steady shear

    PubMed Central

    Forest, M. Gregory; Phuworawong, Panon; Wang, Qi; Zhou, Ruhai

    2014-01-01

    We consider the dilute regime of active suspensions of liquid crystalline polymers (LCPs), addressing issues motivated by our kinetic model and simulations in Forest et al. (Forest et al. 2013 Soft Matter 9, 5207–5222 (doi:10.1039/c3sm27736d)). In particular, we report unsteady two-dimensional heterogeneous flow-orientation attractors for pusher nanorod swimmers at dilute concentrations where passive LCP equilibria are isotropic. These numerical limit cycles are analogous to longwave (homogeneous) tumbling and kayaking limit cycles and two-dimensional heterogeneous unsteady attractors of passive LCPs in weak imposed shear, yet these states arise exclusively at semi-dilute concentrations where stable equilibria are nematic. The results in Forest et al. mentioned above compel two studies in the dilute regime that complement recent work of Saintillan & Shelley (Saintillan & Shelley 2013 C. R. Physique 14, 497–517 (doi:10.1016/j.crhy.2013.04.001)): linearized stability analysis of the isotropic state for nanorod pushers and pullers; and an analytical–numerical study of weakly and strongly sheared active polar nanorod suspensions to capture how particle-scale activation affects shear rheology. We find that weakly sheared dilute puller versus pusher suspensions exhibit steady versus unsteady responses, shear thickening versus thinning and positive versus negative first normal stress differences. These results further establish how sheared dilute nanorod pusher suspensions exhibit many of the characteristic features of sheared semi-dilute passive nanorod suspensions. PMID:25332387

  1. Conserved Active Site Residues Limit Inhibition of a Copper-Containing Nitrite By Small Molecules

    SciTech Connect

    Tocheva, E.I.; Eltis, L.D.; Murphy, M.E.P.

    2009-05-26

    The interaction of copper-containing dissimilatory nitrite reductase from Alcaligenes faecalis S-6 ( AfNiR) with each of five small molecules was studied using crystallography and steady-state kinetics. Structural studies revealed that each small molecule interacted with the oxidized catalytic type 2 copper of AfNiR. Three small molecules (formate, acetate and nitrate) mimic the substrate by having at least two oxygen atoms for bidentate coordination to the type 2 copper atom. These three anions bound to the copper ion in the same asymmetric, bidentate manner as nitrite. Consistent with their weak inhibition of the enzyme ( K i >50 mM), the Cu-O distances in these AfNiR-inhibitor complexes were approximately 0.15 A longer than that observed in the AfNiR-nitrite complex. The binding mode of each inhibitor is determined in part by steric interactions with the side chain of active site residue Ile257. Moreover, the side chain of Asp98, a conserved residue that hydrogen bonds to type 2 copper-bound nitrite and nitric oxide, was either disordered or pointed away from the inhibitors. Acetate and formate inhibited AfNiR in a mixed fashion, consistent with the occurrence of second acetate binding site in the AfNiR-acetate complex that occludes access to the type 2 copper. A fourth small molecule, nitrous oxide, bound to the oxidized metal in a side-on fashion reminiscent of nitric oxide to the reduced copper. Nevertheless, nitrous oxide bound at a farther distance from the metal. The fifth small molecule, azide, inhibited the reduction of nitrite by AfNiR most strongly ( K ic = 2.0 +/- 0.1 mM). This ligand bound to the type 2 copper center end-on with a Cu-N c distance of approximately 2 A, and was the only inhibitor to form a hydrogen bond with Asp98. Overall, the data substantiate the roles of Asp98 and Ile257 in discriminating substrate from other small anions.

  2. Assessing activity limitations in patients with neuromuscular diseases: is the ACTIVLIM questionnaire linked to ICF and ICF-CY?

    PubMed

    Raggi, Alberto; Leonardi, Matilde

    2009-06-01

    The objective of this study was to explore to what extent the ACTIVLIM questionnaire, designed to evaluate limitations in activities involving upper and lower limbs in adults and children with neuromuscular diseases, is linked to the domains of the Activities and Participation of the International Classification of Functioning, Disability and Health (ICF), and to its Children and Youth version (ICF-CY). Standardized ICF linking rules were applied. Items were linked to the most specific ICF-CY codes (e.g. d4501 - Walking long distances), and rolling-up procedures were applied to report information to more generic and informative upper-level codes (e.g. d450 - Walking). ACTIVLIM items were linked to 13 second-level ICF codes of Mobility, Self-care, and Domestic life chapters. The majority of ACTIVLIM items are liked to d510 - Washing oneself, d445 - Hand and arm use, and d410 - Changing basic body position. None of the ACTIVLIM items links to the codes added by the new ICF-CY classification. Disability is a multidimensional phenomenon, and measurements of disability should reflect this multidimensionality. The good psychometric properties of ACTIVLIM are demonstrated, and the aim of this mapping exercise is to provide information on its content. A relevant part of ACTIVLIM items is linked to a few ICF codes, referred to as basic body movements and washing, and other activities are less represented. We think that the ACTIVLIM covers a circumscribed set of activities and, therefore, we suggest using it together with other functional evaluation tools, to complement the range of information on activity limitations that are not covered by its items.

  3. Search for and limits on plume activity on Mimas, Tethys, and Dione with the Cassini Visual Infrared Mapping Spectrometer (VIMS)

    USGS Publications Warehouse

    Buratti, B.J.; Faulk, S.P.; Mosher, J.; Baines, K.H.; Brown, R.H.; Clark, R.N.; Nicholson, P.D.

    2011-01-01

    Cassini Visual Infrared Mapping Spectrometer (VIMS) observations of Mimas, Tethys, and Dione obtained during the nominal and extended missions at large solar phase angles were analyzed to search for plume activity. No forward scattered peaks in the solar phase curves of these satellites were detected. The upper limit on water vapor production for Mimas and Tethys is one order of magnitude less than the production for Enceladus. For Dione, the upper limit is two orders of magnitude less, suggesting this world is as inert as Rhea (Pitman, K.M., Buratti, B.J., Mosher, J.A., Bauer, J.M., Momary, T., Brown, R.H., Nicholson, P.D., Hedman, M.M. [2008]. Astrophys. J. Lett. 680, L65-L68). Although the plumes are best seen at ???2.0. ??m, Imaging Science Subsystem (ISS) Narrow Angle Camera images obtained at the same time as the VIMS data were also inspected for these features. None of the Cassini ISS images shows evidence for plumes. The absence of evidence for any Enceladus-like plumes on the medium-sized saturnian satellites cannot absolutely rule out current geologic activity. The activity may below our threshold of detection, or it may be occurring but not captured on the handful of observations at large solar phase angles obtained for each moon. Many VIMS and ISS images of Enceladus at large solar phase angles, for example, do not contain plumes, as the active "tiger stripes" in the south pole region are pointed away from the spacecraft at these times. The 7-year Cassini Solstice Mission is scheduled to gather additional measurements at large solar phase angles that are capable of revealing activity on the saturnian moons. ?? 2011 Elsevier Inc.

  4. Quantifying planetary limits of Earth system processes relevant to human activity using a thermodynamic view of the whole Earth system

    NASA Astrophysics Data System (ADS)

    Kleidon, Axel

    2014-05-01

    Food, water, and energy play, obviously, a central role in maintaining human activity. In this contribution, I derive estimates for the fundamental limits on the rates by which these resources are provided by Earth system processes and the levels at which these can be used sustainably. The key idea here is that these resources are, directly or indirectly, generated out of the energy associated with the absorption of sunlight, and that the energy conversions from sunlight to other forms ultimately limit the generation of these resources. In order to derive these conversion limits, we need to trace the links between the processes that generate food, water and energy to the absorption of sunlight. The resource "food" results from biomass production by photosynthesis, which requires light and a sufficient magnitude of gas exchange of carbon dioxide at the surface, which is maintained by atmospheric motion which in turn is generated out of differential radiative heating and cooling. The resource "water" is linked to hydrologic cycling, with its magnitude being linked to the latent heat flux of the surface energy balance and water vapor transport in the atmosphere which is also driven by differential radiative heating and cooling. The availability of (renewable) energy is directly related to the generation of different forms of energy of climate system processes, such as the kinetic energy of atmospheric motion, which, again, relates to radiative heating differences. I use thermodynamics and its limits as a basis to establish the planetary limits of these processes and use a simple model to derive first-order estimates. These estimates compare quite well with observations, suggesting that this thermodynamic view of the whole Earth system provides an objective, physical basis to define and quantify planetary boundaries as well as the factors that shape these boundaries.

  5. The internal disruption as hard Magnetohydrodynamic limit of 1/2 sawtooth like activity in large helical device

    SciTech Connect

    Varela, J.; Watanabe, K. Y.; Ohdachi, S.

    2012-08-15

    Large helical device (LHD) inward-shifted configurations are unstable to resistive MHD pressure-gradient-driven modes. Sawtooth like activity was observed during LHD operation. The main drivers are the unstable modes 1/2 and 1/3 in the middle and inner plasma region which limit the plasma confinement efficiency of LHD advanced operation scenarios. The aim of the present research is to study the hard MHD limit of 1/2 sawtooth like activity, not observed yet in LHD operation, and to predict its effects on the device performance. Previous investigations pointed out this system relaxation can be an internal disruption [J. Varela et al., 'Internal disruptions and sawtooth like activity in LHD,' 38th EPS Conference on Plasma Physics (2011), P5.077]. In the present work, we simulate an internal disruption; we study the equilibria properties before and after the disruptive process, its effects on the plasma confinement efficiency during each disruptive phase, the relation between the n/m = 1/2 hard MHD events and the soft MHD events, and how to avoid or reduce their adverse effects. The simulation conclusions point out that the large stochastic region in the middle plasma strongly deforms and tears the flux surfaces when the pressure gradient increases above the hard MHD limit. If the instability reaches the inner plasma, the iota profiles will be perturbed near the plasma core and three magnetic islands can appear near the magnetic axis. If the instability is strong enough to link the stochastic regions in the middle plasma (around the half minor radius {rho}) and the plasma core ({rho}<0.25), an internal disruption is driven.

  6. Lysyl oxidase activity contributes to collagen stabilization during liver fibrosis progression and limits spontaneous fibrosis reversal in mice.

    PubMed

    Liu, Susan B; Ikenaga, Naoki; Peng, Zhen-Wei; Sverdlov, Deanna Y; Greenstein, Andrew; Smith, Victoria; Schuppan, Detlef; Popov, Yury

    2016-04-01

    Collagen stabilization through irreversible cross-linking is thought to promote hepatic fibrosis progression and limit its reversibility. However, the mechanism of this process remains poorly defined. We studied the functional contribution of lysyl oxidase (LOX) to collagen stabilization and hepatic fibrosis progression/reversalin vivousing chronic administration of irreversible LOX inhibitor β-aminopropionitrile (BAPN, or vehicle as control) in C57Bl/6J mice with carbon tetrachloride (CCl4)-induced fibrosis. Fibrotic matrix stability was directly assessed using a stepwise collagen extraction assay and fibrotic septae morphometry. Liver cells and fibrosis were studied by histologic, biochemical methods and quantitative real-time reverse-transcription PCR. During fibrosis progression, BAPN administration suppressed accumulation of cross-linked collagens, and fibrotic septae showed widening and collagen fibrils splitting, reminiscent of remodeling signs observed during fibrosis reversal. LOX inhibition attenuated hepatic stellate cell activation markers and promoted F4/80-positive scar-associated macrophage infiltration without an increase in liver injury. In reversal experiments, BAPN-treated fibrotic mice demonstrated accelerated fibrosis reversal after CCl4withdrawal. Our findings demonstrate for the first time that LOX contributes significantly to collagen stabilization in liver fibrosis, promotes fibrogenic activation of attenuated hepatic stellate cells, and limits fibrosis reversal. Our data support the concept of pharmacologic targeting of LOX pathway to inhibit liver fibrosis and promote its resolution.-Liu, S. B., Ikenaga, N., Peng, Z.-W., Sverdlov, D. Y., Greenstein, A., Smith, V., Schuppan, D., Popov, Y. Lysyl oxidase activity contributes to collagen stabilization during liver fibrosis progression and limits spontaneous fibrosis reversal in mice.

  7. Hormone-sensitive lipase, the rate-limiting enzyme in triglyceride hydrolysis, is expressed and active in beta-cells.

    PubMed

    Mulder, H; Holst, L S; Svensson, H; Degerman, E; Sundler, F; Ahrén, B; Rorsman, P; Holm, C

    1999-01-01

    Triglycerides in the beta-cell may be important for stimulus-secretion coupling, through provision of a lipid-derived signal, and for pathogenetic events in NIDDM, where lipids may adversely affect beta-cell function. In adipose tissues, hormone-sensitive lipase (HSL) is rate-limiting in triglyceride hydrolysis. Here, we investigated whether this enzyme is also expressed and active in beta-cells. Northern blot analysis and reverse transcription-polymerase chain reaction demonstrated that HSL is expressed in rat islets and in the clonal beta-cell lines INS-1, RINm5F, and HIT-T15. Western blot analysis identified HSL in mouse and rat islets and the clonal beta-cells. In mouse and rat, immunocytochemistry showed a predominant occurrence of HSL in beta-cells, with a presumed cytoplasmic localization. Lipase activity in homogenates of the rodent islets and clonal beta-cells constituted 2.1 +/- 0.6% of that in adipocytes; this activity was immunoinhibited by use of antibodies to HSL. The established HSL expression and activity in beta-cells offer a mechanism whereby lipids are mobilized from intracellular stores. Because HSL in adipocytes is activated by cAMP-dependent protein kinase (PKA), PKA-regulated triglyceride hydrolysis in beta-cells may participate in the regulation of insulin secretion, possibly by providing a lipid-derived signal, e.g., long-chain acyl-CoA and diacylglycerol.

  8. The effects of horse riding simulation exercise on muscle activation and limits of stability in the elderly.

    PubMed

    Kim, Seong-Gil; Lee, Jung-Ho

    2015-01-01

    This study aimed to investigate the effect of horse riding simulation (HRS) on balance and trunk muscle activation as well as to provide evidence of the therapeutic benefits of the exercise. Thirty elderly subjects were recruited from a medical care hospital and randomly divided into an experimental and a control group. The experimental group performed the HRS exercise for 20 min, 5 times a week, for 8 weeks, and conventional therapy was also provided as usual. The muscle activation and limits of stability (LOS) were measured. The LOS significantly increased in the HRS group (p<0.05) but not in the control group (p>0.05). The activation of all muscles significantly increased in the HRS group. However, in the control group, the muscle activations of the lateral low-back (external oblique and quadratus lumborum) and gluteus medius (GM) significantly decreased, and there was no significant difference in other muscles. After the intervention, the LOS and all muscle activations significantly increased in the HRS group compared with the control group. The results suggest that the HRS exercise is effective for reducing the overall risk of falling in the elderly. Thus, it is believed that horse riding exercise would help to increase dynamic stability and to prevent elderly people from falling.

  9. Activation of PI3K/Akt pathway limits JNK-mediated apoptosis during EV71 infection.

    PubMed

    Zhang, Hua; Li, Fengqi; Pan, Ziye; Wu, Zhijun; Wang, Yanhong; Cui, Yudong

    2014-11-01

    Apoptosis is frequently induced to inhibit virus replication during infection of Enterovirus 71 (EV71). On the contrary, anti-apoptotic pathway, such as PI3K/Akt pathway, is simultaneously exploited by EV71 to accomplish the viral life cycle. The relationship by which EV71-induced apoptosis and PI3K/Akt signaling pathway remains to be elucidated. In this study, we demonstrated that EV71 infection altered Bax conformation and triggered its redistribution from the cytosol to mitochondria in RD cells. Subsequently, cytochrome c was released from mitochondria to cytosol. We also found that c-Jun NH2-terminal kinase (JNK) was activated during EV71 infection. The JNK specific inhibitor significantly inhibited Bax activation and cytochrome c release, suggesting that EV71-induced apoptosis was involved into a JNK-dependent manner. Meanwhile, EV71-induced Akt phosphorylation involved a PI3K-dependent mechanism. Inhibition of the PI3K/Akt pathway enhanced JNK phosphorylation and the JNK-mediated apoptosis upon EV71 infection. Moreover, PI3K/Akt pathway phosphorylated apoptosis signal-regulating kinase 1 (ASK1) and negatively regulated the ASK1 activity. Knockdown of ASK1 significantly decreased JNK phosphorylation, which implied that ASK1 phosphorylation by Akt inhibited ASK1-mediated JNK activation. Collectively, these data reveal that activation of the PI3K/Akt pathway limits JNK-mediated apoptosis by phosphorylating and inactivating ASK1 during EV71 infection.

  10. The effects of horse riding simulation exercise on muscle activation and limits of stability in the elderly.

    PubMed

    Kim, Seong-Gil; Lee, Jung-Ho

    2015-01-01

    This study aimed to investigate the effect of horse riding simulation (HRS) on balance and trunk muscle activation as well as to provide evidence of the therapeutic benefits of the exercise. Thirty elderly subjects were recruited from a medical care hospital and randomly divided into an experimental and a control group. The experimental group performed the HRS exercise for 20 min, 5 times a week, for 8 weeks, and conventional therapy was also provided as usual. The muscle activation and limits of stability (LOS) were measured. The LOS significantly increased in the HRS group (p<0.05) but not in the control group (p>0.05). The activation of all muscles significantly increased in the HRS group. However, in the control group, the muscle activations of the lateral low-back (external oblique and quadratus lumborum) and gluteus medius (GM) significantly decreased, and there was no significant difference in other muscles. After the intervention, the LOS and all muscle activations significantly increased in the HRS group compared with the control group. The results suggest that the HRS exercise is effective for reducing the overall risk of falling in the elderly. Thus, it is believed that horse riding exercise would help to increase dynamic stability and to prevent elderly people from falling. PMID:25465508

  11. Definition of Small Gram Quantity Contents for Type B Radioactive Material Transportation Packages: Activity-Based Content Limitations

    SciTech Connect

    Sitaraman, S; Kim, S; Biswas, D; Hafner, R; Anderson, B

    2010-10-27

    Since the 1960's, the Department of Transportation Specification (DOT Spec) 6M packages have been used extensively for transportation of Type B quantities of radioactive materials between Department of Energy (DOE) facilities, laboratories, and productions sites. However, due to the advancement of packaging technology, the aging of the 6M packages, and variability in the quality of the packages, the DOT implemented a phased elimination of the 6M specification packages (and other DOT Spec packages) in favor of packages certified to meet federal performance requirements. DOT issued the final rule in the Federal Register on October 1, 2004 requiring that use of the DOT Specification 6M be discontinued as of October 1, 2008. A main driver for the change was the fact that the 6M specification packagings were not supported by a Safety Analysis Report for Packaging (SARP) that was compliant with Title 10 of the Code of Federal Regulations part 71 (10 CFR 71). Therefore, materials that would have historically been shipped in 6M packages are being identified as contents in Type B (and sometimes Type A fissile) package applications and addenda that are to be certified under the requirements of 10 CFR 71. The requirements in 10 CFR 71 include that the Safety Analysis Report for Packaging (SARP) must identify the maximum radioactivity of radioactive constituents and maximum quantities of fissile constituents (10 CFR 71.33(b)(1) and 10 CFR 71.33(b)(2)), and that the application (i.e., SARP submittal or SARP addendum) demonstrates that the external dose rate (due to the maximum radioactivity of radioactive constituents and maximum quantities of fissile constituents) on the surface of the packaging (i.e., package and contents) not exceed 200 mrem/hr (10 CFR 71.35(a), 10 CFR 71.47(a)). It has been proposed that a 'Small Gram Quantity' of radioactive material be defined, such that, when loaded in a transportation package, the dose rates at external points of an unshielded packaging

  12. The thiocarbamate disulphide drug, disulfiram induces osteopenia in rats by inhibition of osteoblast function due to suppression of acetaldehyde dehydrogenase activity.

    PubMed

    Mittal, Monika; Khan, Kainat; Pal, Subhashis; Porwal, Konica; China, Shyamsundar Pal; Barbhuyan, Tarun K; Baghel, Khemraj S; Rawat, Tara; Sanyal, Sabyasachi; Bhadauria, Smrati; Sharma, Vishnu L; Chattopadhyay, Naibedya

    2014-05-01

    Dithiocarbamates (DTC), a sulfhydryl group containing compounds, are extensively used by humans that include metam and thiram due to their pesticide properties, and disulfiram (DSF) as an alcohol deterrent. We screened these DTC in an osteoblast viability assay. DSF exhibited the highest cytotoxicity (IC50 488nM). Loss in osteoblast viability and proliferation was due to induction of apoptosis via G1 arrest. DSF treatment to osteoblasts reduced glutathione (GSH) levels and exogenous addition of GSH prevented DSF-induced reactive oxygen species generation and osteoblast apoptosis. DSF also inhibited osteoblast differentiation in vitro and in vivo, and the effect was associated with inhibition of aldehyde dehydrogenase (ALDH) activity. Out of various ALDH isozymes, osteoblasts expressed only ALDH2 and DSF downregulated its transcript as well as activity. Alda-1, a specific activator of ALDH2, stimulated osteoblast differentiation. Subcutaneous injection of DSF over the calvarium of new born rats reduced the differentiation phenotype of calvarial osteoblasts but increased the mRNA levels of Runx-2 and osteocalcin. DSF treatment at a human-equivalent dose of 30 mg/kg p.o. to adult Sprague Dawley rats caused trabecular osteopenia and suppressed the formation of mineralized nodule by bone marrow stromal cells. Moreover, DSF diminished bone regeneration at the fracture site. In growing rats, DSF diminished growth plate height, primary and secondary spongiosa, mineralized osteoid and trabecular strength. Substantial decreased bone formation was also observed in the cortical site of these rats. We conclude that DSF has a strong osteopenia inducing effect by impairing osteoblast survival and differentiation due to the inhibition of ALDH2 function. PMID:24496638

  13. Characteristic changes in brain electrical activity due to chronic hypoxia in patients with obstructive sleep apnea syndrome (OSAS): a combined EEG study using LORETA and omega complexity.

    PubMed

    Toth, Marton; Faludi, Bela; Wackermann, Jiri; Czopf, Jozsef; Kondakor, Istvan

    2009-11-01

    EEG background activity of patients with obstructive sleep apnea syndrome (OSAS, N = 25) was compared to that of normal controls (N = 14) to reflect alterations of brain electrical activity caused by chronic intermittent hypoxia in OSAS. Global and regional (left vs. right, anterior vs. posterior) measures of spatial complexity (Omega) were used to characterize the degree of spatial synchrony of EEG. Low resolution electromagnetic tomography (LORETA) was used to localize generators of EEG activity in separate frequency bands. Comparing patients to controls, lower Omega complexity was found globally and in the right hemisphere. Using LORETA, an increased medium frequency activity was seen bilaterally in the precuneus, paracentral and posterior cingulate cortex. These findings indicate that alterations caused by chronic hypoxia in brain electrical activity in regions associated with influencing emotional regulation, long-term memory and the default mode network. Global synchronization (lower Omega complexity) may indicate a significantly reduced number of relatively independent, parallel neural processes due to chronic global hypoxic state in apneic patients as well as over the right hemisphere.

  14. Secretion of monocyte chemotactic activity by cultured rat aortic smooth muscle cells in response to PDGF is due predominantly to the induction of JE/MCP-1.

    PubMed Central

    Poon, M.; Hsu, W. C.; Bogdanov, V. Y.; Taubman, M. B.

    1996-01-01

    Inflammation is a critical feature of atherosclerosis and is characterized in part by the migration of circulating monocytes to the atherosclerotic plaque. These monocytes, together with macrophages, are a source of cytokines, growth factors, proteases, and procoagulants, which contribute to the progression of the atherosclerosis lesion. This study employed a modified Boyden chamber to examine the secretion of monocyte chemotactic activity by cultured rat aortic vascular smooth muscle cells in response to growth factors and cytokines. The induction of monocyte chemotactic activity showed a surprising specificity for platelet-derived growth factor-BB. This activity was blocked by actinomycin D and cycloheximide and thus required de novo transcription and protein synthesis. The ability to stimulate monocyte migration appeared to be solely due to the secretion of the monocyte chemoattractant protein JE/MCP-1 and was completely blocked by antisense oligonucleotides and antibodies to JE/MCP-1. The induction of chemotactic activity was also blocked by dexamethasone, an inhibitor of JE mRNA accumulation. This study suggests that the secretion of monocyte chemotactic activity by vascular smooth muscle cells is a highly regulatable and specific event and underscores the importance of JE/MCP-1 in the inflammatory response of the vessel wall. Images Figure 5 PMID:8686755

  15. Older Adults with Diabetes and Osteoarthritis and Their Spouses: Effects of Activity Limitations, Marital Happiness, and Social Contacts on Partners' Daily Mood

    ERIC Educational Resources Information Center

    Roper, Susanne Olsen; Yorgason, Jeremy B.

    2009-01-01

    Using daily diary data from 28 later life couples where one spouse had diabetes and osteoarthritis, we examined crossover effects of target spouses' daily activity limitations and their partners' daily mood. On days when target spouses' daily activity limitations were higher than average, partners' positive mood decreased and negative mood…

  16. False-positive myeloperoxidase binding activity due to DNA/anti-DNA antibody complexes: a source for analytical error in serologic evaluation of anti-neutrophil cytoplasmic autoantibodies.

    PubMed

    Jethwa, H S; Nachman, P H; Falk, R J; Jennette, J C

    2000-09-01

    Anti-myeloperoxidase antibodies (anti-MPO) are a major type of anti-neutrophil cytoplasmic antibody (ANCA). While evaluating anti-MPO monoclonal antibodies from SCG/Kj mice, we observed several hybridomas that appeared to react with both MPO and DNA. Sera from some patients with systemic lupus erythematosus (SLE) also react with MPO and DNA. We hypothesized that the MPO binding activity is a false-positive result due to the binding of DNA, contained within the antigen binding site of anti-DNA antibodies, to the cationic MPO. Antibodies from tissue culture supernatants from 'dual reactive' hybridomas were purified under high-salt conditions (3 M NaCl) to remove any antigen bound to antibody. The MPO and DNA binding activity were measured by ELISA. The MPO binding activity was completely abrogated while the DNA binding activity remained. The MPO binding activity was restored, in a dose-dependent manner, by the addition of increasing amount of calf-thymus DNA (CT-DNA) to the purified antibody. Sera from six patients with SLE that reacted with both MPO and DNA were treated with DNase and showed a decrease in MPO binding activity compared with untreated samples. MPO binding activity was observed when CT-DNA was added to sera from SLE patients that initially reacted with DNA but not with MPO. These results suggest that the DNA contained within the antigen binding site of anti-DNA antibodies could bind to the highly cationic MPO used as substrate antigen in immunoassays, resulting in a false-positive test.

  17. Increased Variation in Adh Enzyme Activity in Drosophila Mutation-Accumulation Experiment Is Not Due to Transposable Elements at the Adh Structural Gene

    PubMed Central

    Aquadro, C. F.; Tachida, H.; Langley, C. H.; Harada, K.; Mukai, T.

    1990-01-01

    We present here a molecular analysis of the region surrounding the structural gene encoding alcohol dehydrogenase (Adh) in 47 lines of Drosophila melanogaster that have each accumulated mutations for 300 generations. While these lines show a significant increase in variation of alcohol dehydrogenase enzyme activity compared to control lines, we found no restriction map variation in a 13-kb region including the complete Adh structural gene and roughly 5 kb of both 5' and 3' sequences. Thus, the rapid accumulation of ADH activity variation after 28,200 allele generations does not appear to have been due to the mobilization of transposable elements into or out of the Adh structural gene region. PMID:1963870

  18. Synthesis of silver nanoparticles through green approach using Dioscorea alata and their characterization on antibacterial activities and optical limiting behavior.

    PubMed

    Pugazhendhi, S; Sathya, P; Palanisamy, P K; Gopalakrishnan, R

    2016-06-01

    In this work, we have successfully synthesized highly biocompatible and functionalized Dioscorea alata (D. alata) mediated silver nanoparticles with different quantities of its extract for the evaluation of proficient bactericidal activity and optical limiting behavior. The crystalline nature of the synthesized silver nanoparticles was confirmed by powder X-ray powder diffraction (XRD) analysis and furthermore confirmed from SAED pattern of HRTEM Analysis. The Surface Plasmon Resonance band was measured and monitored by UV-Visible spectral studies. The functional groups present in the extract for the reduction and stabilization of the nanoparticles were analyzed by Fourier transform infrared spectroscopy (FTIR) technique. Surface morphology and size of particles were determined by high-resolution transmission electron microscopy analysis (HRTEM). The elemental analysis was made by Energy Dispersive X-ray Spectroscopy (EDX). The synthesized silver nanoparticles (AgNPs) in colloidal form were found to exhibit third order optical nonlinearity as studied by closed aperture Z-scan technique and open aperture technique using 532nm Nd:YAG (SHG) CW laser beam (COHERENT-Compass 215M-50 diode-pumped) output as source. The negative nonlinearity observed was well utilized for the study of optical limiting behavior of the silver nanoparticles. D. alata mediated silver nanoparticles possess very good antimicrobial activity which was confirmed by agar well diffusion assay method. PMID:27064188

  19. A limitation of the continuous spectrophotometric assay for the measurement of myo-inositol-1-phosphate synthase activity.

    PubMed

    Huang, Xinyi; Hernick, Marcy

    2011-10-15

    Myo-inositol-1-phosphate synthase (MIPS) catalyzes the conversion of glucose-6-phosphate to myo-inositol-1-phosphate. The reaction catalyzed by MIPS is the first step in the biosynthesis of inositol and inositol-containing molecules that serve important roles in both eukaryotes and prokaryotes. Consequently, MIPS is a target for the development of therapeutic agents for the treatment of infectious diseases and bipolar disorder. We recently reported a continuous spectrophotometric method for measuring MIPS activity using a coupled assay that allows the rapid characterization of MIPS in a multiwell plate format. Here we validate the continuous assay as a high-throughput alternative for measuring MIPS activity and report on one limitation of this assay-the inability to examine the effect of divalent metal ions (at high concentrations) on MIPS activity. In addition, we demonstrate that the activity of MIPS from Arabidopsis thaliana is moderately enhanced by the addition Mg(2+) and is not enhanced by other divalent metal ions (Zn(2+) and Mn(2+)), consistent with what has been observed for other eukaryotic MIPS enzymes. Our findings suggest that the continuous assay is better suited for characterizing eukaryotic MIPS enzymes that require monovalent cations as cofactors than for characterizing bacterial or archeal MIPS enzymes that require divalent metal ions as cofactors. PMID:21729692

  20. Electrochemical flow injection analysis of hydrazine in an excess of an active pharmaceutical ingredient: achieving pharmaceutical detection limits electrochemically.

    PubMed

    Channon, Robert B; Joseph, Maxim B; Bitziou, Eleni; Bristow, Anthony W T; Ray, Andrew D; Macpherson, Julie V

    2015-10-01

    The quantification of genotoxic impurities (GIs) such as hydrazine (HZ) is of critical importance in the pharmaceutical industry in order to uphold drug safety. HZ is a particularly intractable GI and its detection represents a significant technical challenge. Here, we present, for the first time, the use of electrochemical analysis to achieve the required detection limits by the pharmaceutical industry for the detection of HZ in the presence of a large excess of a common active pharmaceutical ingredient (API), acetaminophen (ACM) which itself is redox active, typical of many APIs. A flow injection analysis approach with electrochemical detection (FIA-EC) is utilized, in conjunction with a coplanar boron doped diamond (BDD) microband electrode, insulated in an insulating diamond platform for durability and integrated into a two piece flow cell. In order to separate the electrochemical signature for HZ such that it is not obscured by that of the ACM (present in excess), the BDD electrode is functionalized with Pt nanoparticles (NPs) to significantly shift the half wave potential for HZ oxidation to less positive potentials. Microstereolithography was used to fabricate flow cells with defined hydrodynamics which minimize dispersion of the analyte and optimize detection sensitivity. Importantly, the Pt NPs were shown to be stable under flow, and a limit of detection of 64.5 nM or 0.274 ppm for HZ with respect to the ACM, present in excess, was achieved. This represents the first electrochemical approach which surpasses the required detection limits set by the pharmaceutical industry for HZ detection in the presence of an API and paves the wave for online analysis and application to other GI and API systems. PMID:26302058

  1. An actinomycete isolate from solitary wasp mud nest having strong antibacterial activity and kills the Candida cells due to the shrinkage and the cytosolic loss.

    PubMed

    Kumar, Vijay; Naik, Bindu; Gusain, Omprakash; Bisht, Gajraj S

    2014-01-01

    An actinomycetes strain designated as MN 2(6) was isolated from the solitary wasp mud nest. The isolate was identified using polyphasic taxonomy. It produced the extensive branched brown substrate and white aerial hyphae that changed into grayish black. The aerial mycelia produced the spiral spore chains with rugose spore surface. The growth was observed between temperature range of 27-37°C, pH 8-10 and below salt concentration of 6% (w/v). The comparative analysis of 16S rRNA gene sequence and phylogenetic relationship showed that strain MN 2(6) lies in clade with Streptomyces hygroscopicus subsp. hygroscopicus NRRL 2387(T), Streptomyces sporocinereus NBRC 100766(T) and Streptomyces demainii NRRL B-1478(T) with which it shares a 16S rRNA gene sequence similarity of 99.3%. The strain MN 2(6) can be differentiated from type strains based on phenotypic characteristics. The strain MN 2(6) showed most promising activity against Gram-positive, Gram-negative bacteria, acid-fast bacilli and Candida species suggesting broad-spectrum characteristics of the active metabolite. Evaluation of anti-candidal activity of the metabolite of strain MN 2(6) by scanning electron microscopy (SEM) revealed changed external morphology of yeast. It kills the Candida cells due to the shrinkage and the cytosolic loss. However, further studies are required to elucidate the structure of the active metabolite produced by the isolate MN 2(6).

  2. An actinomycete isolate from solitary wasp mud nest having strong antibacterial activity and kills the Candida cells due to the shrinkage and the cytosolic loss

    PubMed Central

    Kumar, Vijay; Naik, Bindu; Gusain, Omprakash; Bisht, Gajraj S.

    2014-01-01

    An actinomycetes strain designated as MN 2(6) was isolated from the solitary wasp mud nest. The isolate was identified using polyphasic taxonomy. It produced the extensive branched brown substrate and white aerial hyphae that changed into grayish black. The aerial mycelia produced the spiral spore chains with rugose spore surface. The growth was observed between temperature range of 27–37°C, pH 8–10 and below salt concentration of 6% (w/v). The comparative analysis of 16S rRNA gene sequence and phylogenetic relationship showed that strain MN 2(6) lies in clade with Streptomyces hygroscopicus subsp. hygroscopicus NRRL 2387T, Streptomyces sporocinereus NBRC 100766T and Streptomyces demainii NRRL B-1478T with which it shares a 16S rRNA gene sequence similarity of 99.3%. The strain MN 2(6) can be differentiated from type strains based on phenotypic characteristics. The strain MN 2(6) showed most promising activity against Gram-positive, Gram-negative bacteria, acid-fast bacilli and Candida species suggesting broad-spectrum characteristics of the active metabolite. Evaluation of anti-candidal activity of the metabolite of strain MN 2(6) by scanning electron microscopy (SEM) revealed changed external morphology of yeast. It kills the Candida cells due to the shrinkage and the cytosolic loss. However, further studies are required to elucidate the structure of the active metabolite produced by the isolate MN 2(6). PMID:25191320

  3. Measurements and evaluation of the risks due to external radiation exposures and to intake of activated elements for operational staff engaged in the maintenance of medical cyclotrons.

    PubMed

    Calandrino, R; del Vecchio, A; Parisi, R; Todde, S; De Felice, P; Savi, A; Pepe, A; Mrskova, A

    2010-06-01

    The aim of this paper is to assess the activation phenomena and to evaluate the risk of external exposure and intake doses for the maintenance staff of two medical cyclotrons. Two self-shielded cyclotrons are currently operating in the facility for the routine production of (11)C and (18)F. Four radiochemistry laboratories are linked to the cyclotrons by means of shielded radioisotope delivery lines. Radiopharmaceuticals are prepared both for the PET Diagnostic Department, where four CT-PET scanners are operating with a mean patient workload of 40 d(-1) and for [(18)F]FDG external distribution, to provide radiopharmaceuticals for other institutions. In spite of the fact that air contamination inside the radiochemistry laboratories during the synthesis represents the largest 'slice of the pie' in the evaluation of annual intake dose, potential contamination due to the activated particulate, generated during cyclotron irradiation by micro-corrosion of targets and other components potentially struck by the proton beam and generated neutrons, should be considered. In this regard, the most plausible long-lived (T(1/2) > 30 d) radioisotopes formed are: (97)Tc, (56)Co, (57)Co, (58)Co, (60)Co, (49)V, (55)Fe, (109)Cd, (65)Zn and (22)Na. The results for the operating personnel survey has revealed only low-level contamination for (65)Zn in one test, together with minor (18)F intake, probably due to the environmental dispersion of the radioisotope during the [(18)F]FDG synthesis.

  4. Biofilm formation by Staphylococcus epidermidis depends on functional RsbU, an activator of the sigB operon: differential activation mechanisms due to ethanol and salt stress.

    PubMed

    Knobloch, J K; Bartscht, K; Sabottke, A; Rohde, H; Feucht, H H; Mack, D

    2001-04-01

    Staphylococcus epidermidis is a common pathogen in medical device-associated infections. Its major pathogenetic factor is the ability to form adherent biofilms. The polysaccharide intercellular adhesin (PIA), which is synthesized by the products of the icaADBC gene cluster, is essential for biofilm accumulation. In the present study, we characterized the gene locus inactivated by Tn917 insertions of two isogenic, icaADBC-independent, biofilm-negative mutants, M15 and M19, of the biofilm-producing bacterium S. epidermidis 1457. The insertion site was the same in both of the mutants and was located in the first gene, rsbU, of an operon highly homologous to the sigB operons of Staphylococcus aureus and Bacillus subtilis. Supplementation of Trypticase soy broth with NaCl (TSB(NaCl)) or ethanol (TSB(EtOH)), both of which are known activators of sigB, led to increased biofilm formation and PIA synthesis by S. epidermidis 1457. Insertion of Tn917 into rsbU, a positive regulator of alternative sigma factor sigma(B), led to a biofilm-negative phenotype and almost undetectable PIA production. Interestingly, in TSB(EtOH), the mutants were enabled to form a biofilm again with phenotypes similar to those of the wild type. In TSB(NaCl), the mutants still displayed a biofilm-negative phenotype. No difference in primary attachment between the mutants and the wild type was observed. Similar phenotypic changes were observed after transfer of the Tn917 insertion of mutant M15 to the independent and biofilm-producing strain S. epidermidis 8400. In 11 clinical S. epidermidis strains, a restriction fragment length polymorphism of the sigB operon was detected which was independent of the presence of the icaADBC locus and a biofilm-positive phenotype. Obviously, different mechanisms are operative in the regulation of PIA expression in stationary phase and under stress induced by salt or ethanol.

  5. Biofilm formation by Staphylococcus epidermidis depends on functional RsbU, an activator of the sigB operon: differential activation mechanisms due to ethanol and salt stress.

    PubMed

    Knobloch, J K; Bartscht, K; Sabottke, A; Rohde, H; Feucht, H H; Mack, D

    2001-04-01

    Staphylococcus epidermidis is a common pathogen in medical device-associated infections. Its major pathogenetic factor is the ability to form adherent biofilms. The polysaccharide intercellular adhesin (PIA), which is synthesized by the products of the icaADBC gene cluster, is essential for biofilm accumulation. In the present study, we characterized the gene locus inactivated by Tn917 insertions of two isogenic, icaADBC-independent, biofilm-negative mutants, M15 and M19, of the biofilm-producing bacterium S. epidermidis 1457. The insertion site was the same in both of the mutants and was located in the first gene, rsbU, of an operon highly homologous to the sigB operons of Staphylococcus aureus and Bacillus subtilis. Supplementation of Trypticase soy broth with NaCl (TSB(NaCl)) or ethanol (TSB(EtOH)), both of which are known activators of sigB, led to increased biofilm formation and PIA synthesis by S. epidermidis 1457. Insertion of Tn917 into rsbU, a positive regulator of alternative sigma factor sigma(B), led to a biofilm-negative phenotype and almost undetectable PIA production. Interestingly, in TSB(EtOH), the mutants were enabled to form a biofilm again with phenotypes similar to those of the wild type. In TSB(NaCl), the mutants still displayed a biofilm-negative phenotype. No difference in primary attachment between the mutants and the wild type was observed. Similar phenotypic changes were observed after transfer of the Tn917 insertion of mutant M15 to the independent and biofilm-producing strain S. epidermidis 8400. In 11 clinical S. epidermidis strains, a restriction fragment length polymorphism of the sigB operon was detected which was independent of the presence of the icaADBC locus and a biofilm-positive phenotype. Obviously, different mechanisms are operative in the regulation of PIA expression in stationary phase and under stress induced by salt or ethanol. PMID:11274123

  6. Biofilm Formation by Staphylococcus epidermidis Depends on Functional RsbU, an Activator of the sigB Operon: Differential Activation Mechanisms Due to Ethanol and Salt Stress

    PubMed Central

    Knobloch, Johannes K.-M.; Bartscht, Katrin; Sabottke, Axel; Rohde, Holger; Feucht, Heinz-Hubert; Mack, Dietrich

    2001-01-01

    Staphylococcus epidermidis is a common pathogen in medical device-associated infections. Its major pathogenetic factor is the ability to form adherent biofilms. The polysaccharide intercellular adhesin (PIA), which is synthesized by the products of the icaADBC gene cluster, is essential for biofilm accumulation. In the present study, we characterized the gene locus inactivated by Tn917 insertions of two isogenic, icaADBC-independent, biofilm-negative mutants, M15 and M19, of the biofilm-producing bacterium S. epidermidis 1457. The insertion site was the same in both of the mutants and was located in the first gene, rsbU, of an operon highly homologous to the sigB operons of Staphylococcus aureus and Bacillus subtilis. Supplementation of Trypticase soy broth with NaCl (TSBNaCl) or ethanol (TSBEtOH), both of which are known activators of sigB, led to increased biofilm formation and PIA synthesis by S. epidermidis 1457. Insertion of Tn917 into rsbU, a positive regulator of alternative sigma factor ςB, led to a biofilm-negative phenotype and almost undetectable PIA production. Interestingly, in TSBEtOH, the mutants were enabled to form a biofilm again with phenotypes similar to those of the wild type. In TSBNaCl, the mutants still displayed a biofilm-negative phenotype. No difference in primary attachment between the mutants and the wild type was observed. Similar phenotypic changes were observed after transfer of the Tn917 insertion of mutant M15 to the independent and biofilm-producing strain S. epidermidis 8400. In 11 clinical S. epidermidis strains, a restriction fragment length polymorphism of the sigB operon was detected which was independent of the presence of the icaADBC locus and a biofilm-positive phenotype. Obviously, different mechanisms are operative in the regulation of PIA expression in stationary phase and under stress induced by salt or ethanol. PMID:11274123

  7. Limitations in activities of daily living and instrumental activities of daily living capacity in a representative sample: disentangling dementia- and mobility-related effects.

    PubMed

    Wilms, Hans-Ulrich; Riedel-Heller, Steffi G; Angermeyer, Matthias C

    2007-01-01

    A representative sample of the Leipzig population aged 75 years and older showed 61.8% of the participants with relevant deficits in their capacity for independent living, according to a combined activities of daily living/instrumental activities of daily living (ADL/IADL) scale. The quantity and quality of care needed almost exponentially increases above 85 years of age. Looking at potential reasons for ADL/IADL limitations, 44% of variance in single ADL/IADL activities and 75% of the combined ADL/IADL sum score could come from a minimal set of predictor variables. Most important are dementia- or mobility-related declines, but living conditions also explain small but significant amounts of variance. These seem initially impressive, yet analyses showed about half the explained variances shared among the mobility and dementia indicators, limiting the use not only of ADL/IADL sum scores but of many single ADL/IADL items as well. Before deriving specific conclusions from variations in ADL/IADL instruments, one must note that the data suggest that interpretations of covariations--whether for health/mobility or dementia--are useful and substantial only if both indicators/predictors are verified. The information given captures the mobility- and dementia-related variance if ADL/IADL items, facilitating more specific scale developments.

  8. Defective Initiation of Liver Regeneration in Osteopontin-Deficient Mice after Partial Hepatectomy due to Insufficient Activation of IL-6/Stat3 Pathway.

    PubMed

    Wen, Yankai; Feng, Dechun; Wu, Hailong; Liu, Wenjun; Li, Hongjie; Wang, Fang; Xia, Qiang; Gao, Wei-Qiang; Kong, Xiaoni

    2015-01-01

    The initial process in liver regeneration after partial hepatectomy involves the recruitment of immune cells and the release of cytokines. Osteopontin (OPN), a pro-inflammatory protein, plays critical roles in immune cell activation and migration. Although OPN has been implicated in the pathogenesis of many liver diseases, the role of OPN in liver regeneration remains obscure. In the present study, we found that serum and hepatic OPN protein levels were significantly elevated in wild-type (WT) mice after partial hepatectomy (PHx) and that bile ductal epithelia were the major cell source of hepatic OPN. Compared to WT mice, OPN knockout (KO) mice exhibited delayed liver regeneration after PHx. This delay in OPN(-/-) mice was attributed to impaired hepatic infiltration of macrophages and neutrophils, decreased serum and hepatic IL-6 levels, and blunted activation of macrophages after PHx. Furthermore, we demonstrate that the attenuated activation of macrophages is at least partially due to decreased hepatic and portal vein LPS levels in OPN(-/-) mice. In response to decreased IL-6 levels, the activation of signal transducer and transcription (Stat) 3 was reduced in hepatocytes of OPN(-/-) mice compared to WT mice after PHx. Consequently, hepatic activation of the downstream direct targets of IL6/Stat3, such as c-fos, c-jun, and c-myc, was also suppressed post-PHx in OPN(-/-) mice compared to WT mice. Collectively, these results support a unique role for OPN during the priming phase of liver regeneration, in which OPN enhances the recruitment of macrophages and neutrophils, and triggers hepatocyte proliferation through Kupffer cell-derived IL-6 release and the downstream activation of Stat3.

  9. Higher concentrations of nanoscale zero-valent iron (nZVI) in soil induced rice chlorosis due to inhibited active iron transportation.

    PubMed

    Wang, Jie; Fang, Zhanqiang; Cheng, Wen; Yan, Xiaomin; Tsang, Pokeung Eric; Zhao, Dongye

    2016-03-01

    In this study, the effects of concentrations 0, 100, 250, 500, 750 and 1000 mg kg(-1) of nanoscale zero-valent iron (nZVI) on germination, seedlings growth, physiology and toxicity mechanisms were investigated. The results showed that nZVI had no effect on germination, but inhibited the rice seedlings growth in higher concentrations (>500 mg kg(-1) nZVI). The highest suppression rate of the length of roots and shoots reached 46.9% and 57.5%, respectively. The 1000mg kg(-1) nZVI caused the highest suppression rates for chlorophyll and carotenoids, at 91.6% and 85.2%, respectively. In addition, the activity of antioxidant enzymes was altered by the translocation of nanoparticles and changes in active iron content. Visible symptoms of iron deficiency were observed at higher concentrations, at which the active iron content decreased 61.02% in the shoots, but the active iron content not decreased in roots. Interestingly, the total and available amounts of iron in the soil were not less than those in the control. Therefore, the plants iron deficiency was not caused by (i) deficiency of available iron in the soil and (ii) restraint of the absorption that plant takes in the available iron, while induced by (ⅲ) the transport of active iron from the root to the shoot was blocked. The cortex tissues were seriously damaged by nZVI which was transported from soil to the root, these were proved by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). This current study shows that the mechanism of iron deficiency in rice seedling was due to transport of active iron from the root to the shoot blocked, which was caused by the uptake of nZVI.

  10. Higher concentrations of nanoscale zero-valent iron (nZVI) in soil induced rice chlorosis due to inhibited active iron transportation.

    PubMed

    Wang, Jie; Fang, Zhanqiang; Cheng, Wen; Yan, Xiaomin; Tsang, Pokeung Eric; Zhao, Dongye

    2016-03-01

    In this study, the effects of concentrations 0, 100, 250, 500, 750 and 1000 mg kg(-1) of nanoscale zero-valent iron (nZVI) on germination, seedlings growth, physiology and toxicity mechanisms were investigated. The results showed that nZVI had no effect on germination, but inhibited the rice seedlings growth in higher concentrations (>500 mg kg(-1) nZVI). The highest suppression rate of the length of roots and shoots reached 46.9% and 57.5%, respectively. The 1000mg kg(-1) nZVI caused the highest suppression rates for chlorophyll and carotenoids, at 91.6% and 85.2%, respectively. In addition, the activity of antioxidant enzymes was altered by the translocation of nanoparticles and changes in active iron content. Visible symptoms of iron deficiency were observed at higher concentrations, at which the active iron content decreased 61.02% in the shoots, but the active iron content not decreased in roots. Interestingly, the total and available amounts of iron in the soil were not less than those in the control. Therefore, the plants iron deficiency was not caused by (i) deficiency of available iron in the soil and (ii) restraint of the absorption that plant takes in the available iron, while induced by (ⅲ) the transport of active iron from the root to the shoot was blocked. The cortex tissues were seriously damaged by nZVI which was transported from soil to the root, these were proved by scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). This current study shows that the mechanism of iron deficiency in rice seedling was due to transport of active iron from the root to the shoot blocked, which was caused by the uptake of nZVI. PMID:26803790

  11. Pyruvate dehydrogenase kinase isoform 2 activity limited and further inhibited by slowing down the rate of dissociation of ADP.

    PubMed

    Bao, Haiying; Kasten, Shane A; Yan, Xiaohua; Roche, Thomas E

    2004-10-26

    Pyruvate dehydrogenase kinase 2 (PDK2) activity is enhanced by the dihydrolipoyl acetyltransferase core (E2 60mer) that binds PDK2 and a large number of its pyruvate dehydrogenase (E1) substrate. With E2-activated PDK2, K(+) at approximately 90 mM and Cl(-) at approximately 60 mM decreased the K(m) of PDK2 for ATP and competitive K(i) for ADP by approximately 3-fold and enhanced pyruvate inhibition. Comparing PDK2 catalysis +/- E2, E2 increased the K(m) of PDK2 for ATP by nearly 8-fold (from 5 to 39 microM), increased k(cat) by approximately 4-fold, and decreased the requirement for E1 by at least 400-fold. ATP binding, measured by a cold-trapping technique, occurred at two active sites with a K(d) of 5 microM, which equals the K(m) and K(d) of PDK2 for ATP measured in the absence of E2. During E2-aided catalysis, PDK2 had approximately 3 times more ADP than ATP bound at its active site, and the pyruvate analogue, dichloroacetate, led to 16-fold more ADP than ATP being bound (no added ADP). Pyruvate functioned as an uncompetitive inhibitor versus ATP, and inclusion of ADP transformed pyruvate inhibition to noncompetitive. At high pyruvate levels, pyruvate was a partial inhibitor but also induced substrate inhibition at high ATP levels. Our results indicate that, at physiological salt levels, ADP dissociation is a limiting step in E2-activated PDK2 catalysis, that PDK2.[ADP or ATP].pyruvate complexes form, and that PDK2.ATP.pyruvate.E1 reacts with PDK2.ADP.pyruvate accumulating. PMID:15491150

  12. Yeast growth in raffinose results in resistance to acetic-acid induced programmed cell death mostly due to the activation of the mitochondrial retrograde pathway.

    PubMed

    Guaragnella, Nicoletta; Zdralević, Maša; Lattanzio, Paolo; Marzulli, Domenico; Pracheil, Tammy; Liu, Zhengchang; Passarella, Salvatore; Marra, Ersilia; Giannattasio, Sergio

    2013-12-01

    In order to investigate whether and how a modification of mitochondrial metabolism can affect yeast sensitivity to programmed cell death (PCD) induced by acetic acid (AA-PCD), yeast cells were grown on raffinose, as a sole carbon source, which, differently from glucose, favours mitochondrial respiration. We found that, differently from glucose-grown cells, raffinose-grown cells were mostly resistant to AA-PCD and that this was due to the activation of mitochondrial retrograde (RTG) response, which increased with time, as revealed by the up-regulation of the peroxisomal isoform of citrate synthase and isocitrate dehydrogenase isoform 1, RTG pathway target genes. Accordingly, the deletion of RTG2 and RTG3, a positive regulator and a transcription factor of the RTG pathway, resulted in AA-PCD, as shown by TUNEL assay. Neither deletion in raffinose-grown cells of HAP4, encoding the positive regulatory subunit of the Hap2,3,4,5 complex nor constitutive activation of the RTG pathway in glucose-grown cells due to deletion of MKS1, a negative regulator of RTG pathway, had effect on yeast AA-PCD. The RTG pathway was found to be activated in yeast cells containing mitochondria, in which membrane potential was measured, capable to consume oxygen in a manner stimulated by the uncoupler CCCP and inhibited by the respiratory chain inhibitor antimycin A. AA-PCD resistance in raffinose-grown cells occurs with a decrease in both ROS production and cytochrome c release as compared to glucose-grown cells en route to AA-PCD. PMID:23906793

  13. Yeast growth in raffinose results in resistance to acetic-acid induced programmed cell death mostly due to the activation of the mitochondrial retrograde pathway.

    PubMed

    Guaragnella, Nicoletta; Zdralević, Maša; Lattanzio, Paolo; Marzulli, Domenico; Pracheil, Tammy; Liu, Zhengchang; Passarella, Salvatore; Marra, Ersilia; Giannattasio, Sergio

    2013-12-01

    In order to investigate whether and how a modification of mitochondrial metabolism can affect yeast sensitivity to programmed cell death (PCD) induced by acetic acid (AA-PCD), yeast cells were grown on raffinose, as a sole carbon source, which, differently from glucose, favours mitochondrial respiration. We found that, differently from glucose-grown cells, raffinose-grown cells were mostly resistant to AA-PCD and that this was due to the activation of mitochondrial retrograde (RTG) response, which increased with time, as revealed by the up-regulation of the peroxisomal isoform of citrate synthase and isocitrate dehydrogenase isoform 1, RTG pathway target genes. Accordingly, the deletion of RTG2 and RTG3, a positive regulator and a transcription factor of the RTG pathway, resulted in AA-PCD, as shown by TUNEL assay. Neither deletion in raffinose-grown cells of HAP4, encoding the positive regulatory subunit of the Hap2,3,4,5 complex nor constitutive activation of the RTG pathway in glucose-grown cells due to deletion of MKS1, a negative regulator of RTG pathway, had effect on yeast AA-PCD. The RTG pathway was found to be activated in yeast cells containing mitochondria, in which membrane potential was measured, capable to consume oxygen in a manner stimulated by the uncoupler CCCP and inhibited by the respiratory chain inhibitor antimycin A. AA-PCD resistance in raffinose-grown cells occurs with a decrease in both ROS production and cytochrome c release as compared to glucose-grown cells en route to AA-PCD.

  14. Short-term 222Rn activity concentration changes in underground spaces with limited air exchange with the atmosphere

    NASA Astrophysics Data System (ADS)

    Fijałkowska-Lichwa, L.; Przylibski, T. A.

    2011-04-01

    The authors investigated short-time changes in 222Rn activity concentration occurring yearly in two underground tourist facilities with limited air exchange with the atmosphere. One of them is Niedźwiedzia (Bear) Cave in Kletno, Poland - a natural space equipped with locks ensuring isolation from the atmosphere. The other site is Fluorite Adit in Kletno, a section of a disused uranium mine. This adit is equipped with a mechanical ventilation system, operated periodically outside the opening times (at night). Both sites are situated within the same metamorphic rock complex, at similar altitudes, about 2 km apart. The measurements conducted revealed spring and autumn occurrence of convective air movements. In Bear Cave, this process causes a reduction in 222Rn activity concentration in the daytime, i.e. when tourists, guides and other staff are present in the cave. From the point of view of radiation protection, this is the best situation. For the rest of the year, daily concentrations of 222Rn activity in the cave are very stable. In Fluorite Adit, on the other hand, significant variations in daily 222Rn activity concentrations are recorded almost all year round. These changes are determined by the periods of activity and inactivity of mechanical ventilation. Unfortunately this is inactive in the daytime, which results in the highest values of 222Rn activity concentration at the times when tourists and staff are present in the adit. Slightly lower concentrations of radon in Fluorite Adit are recorded in the winter season, when convective air movements carry a substantial amount of radon out into the atmosphere. The incorrect usage of mechanical ventilation in Fluorite Adit results in the most unfavourable conditions in terms of radiation protection. The staff working in that facility are exposed practically throughout the year to the highest 222Rn activity concentrations, both at work (in the adit) and at home (outside their working hours). Therefore, not very well

  15. CD11b regulates obesity-induced insulin resistance via limiting alternative activation and proliferation of adipose tissue macrophages

    PubMed Central

    Zheng, Chunxing; Yang, Qian; Xu, Chunliang; Cao, Jianchang; Jiang, Menghui; Chen, Qing; Cao, Gang; Han, Yanyan; Li, Fengying; Cao, Wei; Zhang, Liying; Zhang, Li; Shi, Yufang; Wang, Ying

    2015-01-01

    Obesity-associated inflammation is accompanied by the accumulation of adipose tissue macrophages (ATMs), which is believed to predispose obese individuals to insulin resistance. CD11b (integrin αM) is highly expressed on monocytes and macrophages and is critical for their migration and function. We found here that high-fat diet–induced insulin resistance was significantly reduced in CD11b-deficient mice. Interestingly, the recruitment of monocytes to adipose tissue is impaired when CD11b is deficient, although the cellularity of ATMs in CD11b-deficient mice is higher than that in wild-type mice. We further found that the increase in ATMs is caused mainly by their vigorous proliferation in the absence of CD11b. Moreover, the proliferation and alternative activation of ATMs are regulated by the IL-4/STAT6 axis, which is inhibited by CD11b through the activity of phosphatase SHP-1. Thus, CD11b plays a critical role in obesity-induced insulin resistance by limiting the proliferation and alternative activation of ATMs. PMID:26669445

  16. Activation of MAPK pathways due to DUSP4 loss promotes cancer stem cell-like phenotypes in basal-like breast cancer.

    PubMed

    Balko, Justin M; Schwarz, Luis J; Bhola, Neil E; Kurupi, Richard; Owens, Phillip; Miller, Todd W; Gómez, Henry; Cook, Rebecca S; Arteaga, Carlos L

    2013-10-15

    Basal-like breast cancer (BLBC) is an aggressive disease that lacks a clinically approved targeted therapy. Traditional chemotherapy is effective in BLBC, but it spares the cancer stem cell (CSC)-like population, which is likely to contribute to cancer recurrence after the initial treatment. Dual specificity phosphatase-4 (DUSP4) is a negative regulator of the mitogen-activated protein kinase (MAPK) pathway that is deficient in highly aggressive BLBCs treated with chemotherapy, leading to aberrant MAPK activation and resistance to taxane-induced apoptosis. Herein, we investigated how DUSP4 regulates the MAP-ERK kinase (MEK) and c-jun-NH2-kinase (JNK) pathways in modifying CSC-like behavior. DUSP4 loss increased mammosphere formation and the expression of the CSC-promoting cytokines interleukin (IL)-6 and IL-8. These effects were caused in part by loss of control of the MEK and JNK pathways and involved downstream activation of the ETS-1 and c-JUN transcription factors. Enforced expression of DUSP4 reduced the CD44(+)/CD24(-) population in multiple BLBC cell lines in a MEK-dependent manner, limiting tumor formation of claudin-low SUM159PT cells in mice. Our findings support the evaluation of MEK and JNK pathway inhibitors as therapeutic agents in BLBC to eliminate the CSC population.

  17. Heterozygous splice mutation in PIK3R1 causes human immunodeficiency with lymphoproliferation due to dominant activation of PI3K

    PubMed Central

    Lucas, Carrie L.; Zhang, Yu; Venida, Anthony; Wang, Ying; Hughes, Jason; McElwee, Joshua; Butrick, Morgan; Matthews, Helen; Price, Susan; Biancalana, Matthew; Wang, Xiaochuan; Richards, Michael; Pozos, Tamara; Barlan, Isil; Ozen, Ahmet; Rao, V. Koneti; Su, Helen C.

    2014-01-01

    Class IA phosphatidylinositol 3-kinases (PI3K), which generate PIP3 as a signal for cell growth and proliferation, exist as an intracellular complex of a catalytic subunit bound to a regulatory subunit. We and others have previously reported that heterozygous mutations in PIK3CD encoding the p110δ catalytic PI3K subunit cause a unique disorder termed p110δ-activating mutations causing senescent T cells, lymphadenopathy, and immunodeficiency (PASLI) disease. We report four patients from three families with a similar disease who harbor a recently reported heterozygous splice site mutation in PIK3R1, which encodes the p85α, p55α, and p50α regulatory PI3K subunits. These patients suffer from recurrent sinopulmonary infections and lymphoproliferation, exhibit hyperactive PI3K signaling, and have prominent expansion and skewing of peripheral blood CD8+ T cells toward terminally differentiated senescent effector cells with short telomeres. The PIK3R1 splice site mutation causes skipping of an exon, corresponding to loss of amino acid residues 434–475 in the inter-SH2 domain. The mutant p85α protein is expressed at low levels in patient cells and activates PI3K signaling when overexpressed in T cells from healthy subjects due to qualitative and quantitative binding changes in the p85α–p110δ complex and failure of the C-terminal region to properly inhibit p110δ catalytic activity. PMID:25488983

  18. Triosephosphate isomerase deficiency: haemolytic anaemia, myopathy with altered mitochondria and mental retardation due to a new variant with accelerated enzyme catabolism and diminished specific activity.

    PubMed

    Eber, S W; Pekrun, A; Bardosi, A; Gahr, M; Krietsch, W K; Krüger, J; Matthei, R; Schröter, W

    1991-09-01

    A new triosephosphate isomerase (TPI) variant is described in an 8-year-old Turkish girl suffering from chronic haemolytic anaemia, myopathy and developmental retardation since early infancy. The enzyme activity profile revealed a generalized deficiency in erythrocytes, granulocytes, mononuclear blood cells, skeletal muscle tissue and cerebrospinal fluid. The concentration of enzyme substrate dihydroxyacetone phosphate was distinctly elevated. Biochemical examination showed accelerated enzyme deamidation, the first step in the normal catabolism of TPI during aging of the erythrocyte. The specific activity of the variant TPI, determined by antibody titration, was reduced to 61% of normal. Its heat stability was markedly decreased. Muscle biopsy and neuropsychological testing further clarified the pathogenesis of the disorder. A prevalent alteration of mitochondria similar to that seen in mitochondrial myopathy and an elevated amount of intracellular glycogen were found. The patient's retarded intellectual development was mainly due to impaired visual perception and sensory-motor co-ordination in addition to a lack of syllogistic reasoning. The findings indicate that the low TPI activity leads to a metabolic block of the glycolytic pathway and hence to a generalized impairment of cellular energy supply.

  19. Real-Time Human Ambulation, Activity, and Physiological Monitoring: Taxonomy of Issues, Techniques, Applications, Challenges and Limitations

    PubMed Central

    Khusainov, Rinat; Azzi, Djamel; Achumba, Ifeyinwa E.; Bersch, Sebastian D.

    2013-01-01

    Automated methods of real-time, unobtrusive, human ambulation, activity, and wellness monitoring and data analysis using various algorithmic techniques have been subjects of intense research. The general aim is to devise effective means of addressing the demands of assisted living, rehabilitation, and clinical observation and assessment through sensor-based monitoring. The research studies have resulted in a large amount of literature. This paper presents a holistic articulation of the research studies and offers comprehensive insights along four main axes: distribution of existing studies; monitoring device framework and sensor types; data collection, processing and analysis; and applications, limitations and challenges. The aim is to present a systematic and most complete study of literature in the area in order to identify research gaps and prioritize future research directions. PMID:24072027

  20. A one-layer recurrent neural network with a discontinuous hard-limiting activation function for quadratic programming.

    PubMed

    Liu, Q; Wang, J

    2008-04-01

    In this paper, a one-layer recurrent neural network with a discontinuous hard-limiting activation function is proposed for quadratic programming. This neural network is capable of solving a large class of quadratic programming problems. The state variables of the neural network are proven to be globally stable and the output variables are proven to be convergent to optimal solutions as long as the objective function is strictly convex on a set defined by the equality constraints. In addition, a sequential quadratic programming approach based on the proposed recurrent neural network is developed for general nonlinear programming. Simulation results on numerical examples and support vector machine (SVM) learning show the effectiveness and performance of the neural network.

  1. Health Literacy, Physician Trust, and Diabetes-related Self-care Activities in Hispanics with Limited Resources

    PubMed Central

    White, Richard O.; Osborn, Chandra Y.; Gebretsadik, Tebeb; Kripalani, Sunil; Rothman, Russell L.

    2014-01-01

    Background Hispanics with diabetes often have deficits in health literacy (HL). We examined the association among HL, psychosocial factors, and diabetes-related self-care activities. Methods Cross-sectional analysis of 149 patients. Data included patient demographics and validated measures of HL, physician trust, self-efficacy, acculturation, self-care behaviors, and A1c. Results Participants (N=60) with limited HL were older and less educated, and had more years with diabetes compared with adequate HL participants (N=89). Limited HL participants reported greater trust in their physician, greater self-efficacy, and better diet, foot care, and medication adherence. Health literacy status was not associated with acculturation or A1c. In adjusted analyses, HL status remained associated with physician trust, and we observed a notable but nonsignificant trend between HL status and medication adherence. Discussion Lower HL was associated with greater physician trust and better medication adherence. Further research is warranted to clarify the role of HL and physician trust in optimizing self-care for Hispanics. PMID:24185168

  2. Reducing IRF-1 to Levels Observed in HESN Subjects Limits HIV Replication, But Not the Extent of Host Immune Activation.

    PubMed

    Su, Ruey-Chyi; Plesniarski, Andrew; Ao, Zhujun; Kimani, Joshua; Sivro, Aida; Jaoko, Walter; Plummer, Frank A; Yao, Xiaojian; Ball, Terry Blake

    2015-01-01

    Cells from women who are epidemiologically deemed resistant to HIV infection exhibit a 40-60% reduction in endogenous IRF-1 (interferon regulatory factor-1), an essential regulator of host antiviral immunity and the early HIV replication. This study examined the functional consequences of reducing endogenous IRF-1 on HIV-1 replication and immune response to HIV in natural HIV target cells. IRF-1 knockdown was achieved in ex vivo CD4(+) T cells and monocytes with siRNA. IRF-1 level was assessed using flow cytometry, prior to infection with HIV-Bal, HIV-IIIB, or HIV-VSV-G. Transactivation of HIV long terminal repeats was assessed by p24 secretion (ELISA) and Gag expression (reverse transcription-polymerase chain reaction (RT-PCR)). The expression of IRF-1-regulated antiviral genes was quantitated with RT-PCR. A modest 20-40% reduction in endogenous IRF-1 was achieved in >87% of ex vivo-derived peripheral CD4(+) T cells and monocytes, resulted in >90% reduction in the transactivation of the HIV-1 genes (Gag, p24) and, hence, HIV replication. Curiously, these HIV-resistant women demonstrated normal immune responses, nor an increased susceptibility to other infection. Similarly, modest IRF-1 knockdown had limited impact on the magnitude of HIV-1-elicited activation of IRF-1-regulated host immunologic genes but resulted in lessened duration of these responses. These data suggest that early expression of HIV-1 genes requires a higher IRF-1 level, compared to the host antiviral genes. Together, these provide one key mechanism underlying the natural resistance against HIV infection and further suggest that modest IRF-1 reduction could effectively limit productive HIV infection yet remain sufficient to activate a robust but transient immune response. PMID:26506037

  3. Partial root zone drying: regulation of photosynthetic limitations and antioxidant enzymatic activities in young olive (Olea europaea) saplings.

    PubMed

    Aganchich, Badia; Wahbi, Said; Loreto, Francesco; Centritto, Mauro

    2009-05-01

    The effect of partial root drying (PRD) irrigation on split-root olive (Olea europaea L. cv Picholine marocaine) saplings was investigated. An irrigated control and two PRD regimes were applied (control: irrigation applied on both sides of the root system to keep the soil water content close to field capacity; PRD(50): irrigation applied at 50% of the control amount on one side of the root system and irrigation withheld from the other side, with irrigation regimes switched between the sides of the root system every 2 weeks; and PRD(100): irrigation applied at 100% of the control amount on one side and irrigation withheld on the other side, with irrigation regimes switched between the sides of the root system every 2 weeks. Only saplings in the PRD(50) regime were subjected to water-deficit irrigation. The PRD treatments significantly affected water relations and vegetative growth throughout the growing season. Predawn leaf water potential and relative water content differed significantly between the PRD(50) and PRD(100) saplings, leading to reduced stomatal conductance, carbon assimilation, shoot length and leaf number in PRD(50) saplings. However, the PRD(50) water-deficit treatment did not affect the capacity of the saplings to assimilate CO(2). Activities of superoxide dismutase, soluble and insoluble peroxidase (POX) and polyphenol oxidase were up-regulated by the PRD(50) and PRD(100) treatments compared with control values. The higher activities of both soluble and insoluble POX observed in PRD(50) saplings may reflect the greater inhibitory effect of this treatment on vegetative growth. Up-regulation of the detoxifying systems in the PRD(100) and PRD(50) saplings may have provided protection mechanisms against irreversible damage to the photosynthetic machinery, thereby allowing the photosynthetic apparatus to function and preventing the development of severe water stress. We also measured CO(2) assimilation rate/internal leaf CO(2) concentration (A

  4. Preventing Slips and Falls through Leisure-Time Physical Activity: Findings from a Study of Limited-Service Restaurants

    PubMed Central

    Caban-Martinez, Alberto J.; Courtney, Theodore K.; Chang, Wen-Ruey; Lombardi, David A.; Huang, Yueng-Hsiang; Brennan, Melanye J.; Perry, Melissa J.; Katz, Jeffrey N.; Verma, Santosh K.

    2014-01-01

    Background/Objective Physical activity has been shown to be beneficial at improving health in some medical conditions and in preventing injury. Epidemiologic studies suggest that physical activity is one factor associated with a decreased risk for slips and falls in the older (≥65 years) adult population. While the risk of slips and falls is generally lower in younger than in older adults; little is known of the relative contribution of physical activity in preventing slips and falls in younger adults. We examined whether engagement in leisure-time physical activity (LTPA) was protective of slips and falls among a younger/middle-aged (≤50 years old) working population. Methods 475 workers from 36 limited-service restaurants in six states in the U.S. were recruited to participate in a prospective cohort study of workplace slipping. Information on LTPA was collected at the time of enrollment. Participants reported their slip experience and work hours weekly for up to 12 weeks. We investigated the association between the rate of slipping and the rate of major slipping (i.e., slips that resulted in a fall and/or injury) and LTPA for workers 50 years of age and younger (n = 433, range 18–50 years old) using a multivariable negative binomial generalized estimating equation model. Results The rate of major slips among workers who engaged in moderate (Adjusted Rate Ratio (RR)  = 0.65; 95% Confidence Interval (CI)  =  [0.18–2.44]) and vigorous (RR = 0.64; 95%CI  =  [0.18–2.26]) LTPA, while non-significant, were approximately one-third lower than the rate of major slips among less active workers. Conclusion While not statistically significant, the results suggest a potential association between engagement in moderate and vigorous LTPA and the rate of major slips in younger adults. Additional studies that examine the role of occupational and non-occupational physical activity on the risk of slips, trips and falls among younger and middle aged

  5. Metabolites related to gut bacterial metabolism, peroxisome proliferator-activated receptor-alpha activation, and insulin sensitivity are associated with physical function in functionally-limited older adults.

    PubMed

    Lustgarten, Michael S; Price, Lori L; Chalé, Angela; Fielding, Roger A

    2014-10-01

    Identification of mechanisms underlying physical function will be important for addressing the growing challenge that health care will face with physical disablement in the expanding aging population. Therefore, the goals of the current study were to use metabolic profiling to provide insight into biologic mechanisms that may underlie physical function by examining the association between baseline and the 6-month change in serum mass spectrometry-obtained amino acids, fatty acids, and acylcarnitines with baseline and the 6-month change in muscle strength (leg press one repetition maximum divided by total lean mass, LP/Lean), lower extremity function [short physical performance battery (SPPB)], and mobility (400 m gait speed, 400-m), in response to 6 months of a combined resistance exercise and nutritional supplementation (whey protein or placebo) intervention in functionally-limited older adults (SPPB ≤ 10; 70-85 years, N = 73). Metabolites related to gut bacterial metabolism (cinnamoylglycine, phenol sulfate, p-cresol sulfate, 3-indoxyl sulfate, serotonin, N-methylproline, hydrocinnamate, dimethylglycine, trans-urocanate, valerate) that are altered in response to peroxisome proliferator-activated receptor-alpha (PPAR-α) activation (α-hydroxyisocaproate, α-hydroxyisovalerate, 2-hydroxy-3-methylvalerate, indolelactate, serotonin, 2-hydroxypalmitate, glutarylcarnitine, isobutyrylcarnitine, cinnamoylglycine) and that are related to insulin sensitivity (monounsaturated fatty acids: 5-dodecenoate, myristoleate, palmitoleate; γ-glutamylamino acids: γ-glutamylglutamine, γ-glutamylalanine, γ-glutamylmethionine, γ-glutamyltyrosine; branched-chain amino acids: leucine, isoleucine, valine) were associated with function at baseline, with the 6-month change in function or were identified in backward elimination regression predictive models. Collectively, these data suggest that gut microbial metabolism, PPAR-α activation, and insulin sensitivity may be involved in

  6. Prevalence of doctor-diagnosed arthritis and arthritis-attributable activity limitation--United States, 2010-2012.

    PubMed

    2013-11-01

    Arthritis is the most common cause of disability among U.S. adults and is particularly common among persons with multiple chronic conditions. In 2003, arthritis in the United States resulted in an estimated $128 billion in medical-care costs and lost earnings. To update previous U.S. estimates of the prevalence of doctor-diagnosed arthritis and arthritis-attributable activity limitation (AAAL), CDC analyzed 2010-2012 data from the National Health Interview Survey (NHIS). This report summarizes the results of that analysis, which found that 52.5 million (22.7%) of adults aged ≥18 years had self-reported doctor-diagnosed arthritis, and 22.7 million (9.8%, or 43.2% of those with arthritis) reported AAAL, matching and exceeding previous projected increases, respectively. Among persons with heart disease, diabetes, and obesity, the prevalences of doctor-diagnosed arthritis were 49.0%, 47.3%, and 31.2%, respectively; the prevalences of AAAL among persons with these specific conditions were 26.8%, 25.7%, and 15.2%, respectively. Greater use of evidence-based interventions, such as chronic disease self-management education and physical activity interventions that have been proven to reduce pain and improve quality-of-life among adults with chronic diseases might help reduce the personal and societal burden of arthritis. PMID:24196662

  7. SERS activity with tenfold detection limit optimization on a type of nanoporous AAO-based complex multilayer substrate.

    PubMed

    Sui, Chaofan; Wang, Kaige; Wang, Shuang; Ren, Junying; Bai, Xiaohong; Bai, Jintao

    2016-03-21

    Most of SERS applications are constricted by heterogeneous hotspots and aggregates of nanostructure, which result in low sensitivity and poor reproducibility of characteristic signals. This work intends to introduce SERS properties of a type of SERS-active substrate, Au-CuCl2-AAO, which is innovatively developed on a porous anodic alumina oxide (AAO) template. Spectral measuring results of Rhodamine 6G (R6G) on this substrate optimized by controlling morphology and gold thickness showed that enhancement factor (2.30 × 10(7)) and detection limit (10(-10) M) were both improved and represented better performance than its template AAO. Homogenous hot spots across the region of interest were achieved by scanning SERS intensity distribution for the band at 1505 cm(-1) in 5 × 5 μm(2) area. Furthermore, the promising SERS activity of the flower-patterned substrate was theoretically explained through simulation of the electromagnetic field distribution. In addition, this SERS substrate is proposed for applications within the field of chemical and biochemical analyses. PMID:26911325

  8. Challenges to Understand Stellar Chromospheres and Stellar Activity: The Limit Case of Late-A and Early-F Stars

    NASA Astrophysics Data System (ADS)

    Freire Ferrero, R.; Gouttebroze, P.

    The onset of chromospheric activity appears at late-A and early-F stars where theories predict atmospheres in radiative equilibrium and shallow or non-existent convective zones. The detection of Ly-α emission cores in several A and F stars, first with the IUE satellite and then with the HST, gives evidence for the presence of chromospheric layers in these stars up to B - V = 0. ^m19 (Catalano et al. [CITE]). Semiempirical chromospheric models for Altair allowed us (Freire et al. [CITE]) to explain the observed emission profiles taking into account normal HI IS absorption. However, due to the very high rotational velocity we analyzed alternative hypotheses like the formation of Ly-α emissions into a corotating expanding wind, but we ruled out this alternative because we obtained inconsistent results. In addition, X-ray emission (originated surely in a corona) strengthen the presence of a chromosphere. Here we place the problem of chromospheric activity of late-A and early-F stars in the general context of the formation of over-photospheric stellar layers, comparing them with late-type star and solar cases.

  9. Conducting financial due diligence of medical practices.

    PubMed

    Louiselle, P

    1995-12-01

    Many healthcare organizations are acquiring medical practices in an effort to build more integrated systems of healthcare products and services. This acquisition activity must be approached cautiously to ensure that medical practices being acquired do not have deficiencies that would jeopardize integration efforts. Conducting a thorough due diligence analysis of medical practices before finalizing the transaction can limit the acquiring organizations' legal and financial exposure and is a necessary component to the acquisition process. The author discusses the components of a successful financial due diligence analysis and addresses some of the risk factors in a practice acquisition. PMID:10152892

  10. Distinct expression of alkaline phosphatase activity in epilimnetic bacteria: Implication for persistent DOC consumption in a P-limited reservoir

    NASA Astrophysics Data System (ADS)

    Tseng, Y.; Kao, S.; Shiah, F.

    2013-12-01

    In a P-deficient system, P availability usually controls the microbial activity and thus the ecosystem function. Thingstad et al. (1997) first addressed a 'Malfunctioning Microbial-loop' theory, which stated that low bacterial production (BP) caused by insufficient nutrient supply would result in DOC accumulation in an oligotrophic ecosystem. In this study we re-examined the theory by conducting seasonal patterns and correlations among soluble reactive phosphate (SRP) and DOC, microbial abundances (picocyanobacteria, bacteria, and heterotrophic nanoflagellate; HNF) and activities (primary production, bacterial production, and alkaline phosphatase activity; APA) coupled with enzyme-labeled fluorescence (ELF) assays on bacterioplankton in a subtropical reservoir sharing the common features, nitrate-replete and P-deficient, with most natural freshwater system during Oct 2007-Oct 2008. Persistently high APA was recorded during most of time, implying that the system was P-deficient. Size fractionated APA and ELF assay revealed that bacteria were the major APA contributor. However, significantly low epilimnion DOC was recorded during the stratified summer season accompanying with high BP and APA as well as high PP, implying that heterotrophic bacteria can well sustain in P-deficient system by utilizing DOP to rapidly lower down DOC under relatively high PP. Such findings oppose the 'Malfunctioning Microbial-loop' theory. On the other hand, strong epilimnetic DOC accumulation occurred in Oct 2007 under low light and low PP condition accompanying with high abundance of HNF, implying that HNF grazing may contribute to a certain degree of DOC accumulation. Correlation matrix supported our suggestions. This study testified the DOC dynamics in P-deficient ecosystem are tightly coupled with the source (PP and grazing) and sink (BP). We also suggested that in SRP-limited freshwater systems bacteria are capable of breaking down autochthonous DOC to reduce the chance of DOC

  11. Testing the limits of rational design by engineering pH sensitivity into membrane-active peptides.

    PubMed

    Wiedman, Gregory; Wimley, William C; Hristova, Kalina

    2015-04-01

    In this work, we sought to rationally design membrane-active peptides that are triggered by low pH to form macromolecular-sized pores in lipid bilayers. Such peptides could have broad utility in biotechnology and in nanomedicine as cancer therapeutics or drug delivery vehicles that promote release of macromolecules from endosomes. Our approach to rational design was to combine the properties of a pH-independent peptide, MelP5, which forms large pores allowing passage of macromolecules, with the properties of two pH-dependent membrane-active peptides, pHlip and GALA. We created two hybrid sequences, MelP5_Δ4 and MelP5_Δ6, by using the distribution of acidic residues on pHlip and GALA as a guide to insert acidic amino acids into the amphipathic helix of MelP5. We show that the new peptides bind to lipid bilayers and acquire secondary structure in a pH-dependent manner. The peptides also destabilize bilayers in a pH-dependent manner, such that lipid vesicles release the small molecules ANTS/DPX at low pH only. Thus, we were successful in designing pH-triggered pore-forming peptides. However, no macromolecular release was observed under any conditions. Therefore, we abolished the unique macromolecular poration properties of MelP5 by introducing pH sensitivity into its sequence. We conclude that the properties of pHlip, GALA, and MelP5 are additive, but only partially so. We propose that this lack of additivity is a limitation in the rational design of novel membrane-active peptides, and that high-throughput approaches to discovery will be critical for continued progress in the field.

  12. Low resting metabolic rate in exercise-associated amenorrhea is not due to a reduced proportion of highly active metabolic tissue compartments.

    PubMed

    Koehler, Karsten; Williams, Nancy I; Mallinson, Rebecca J; Southmayd, Emily A; Allaway, Heather C M; De Souza, Mary Jane

    2016-08-01

    Exercising women with menstrual disturbances frequently display a low resting metabolic rate (RMR) when RMR is expressed relative to body size or lean mass. However, normalizing RMR for body size or lean mass does not account for potential differences in the size of tissue compartments with varying metabolic activities. To explore whether the apparent RMR suppression in women with exercise-associated amenorrhea is a consequence of a lower proportion of highly active metabolic tissue compartments or the result of metabolic adaptations related to energy conservation at the tissue level, RMR and metabolic tissue compartments were compared among exercising women with amenorrhea (AMEN; n = 42) and exercising women with eumenorrheic, ovulatory menstrual cycles (OV; n = 37). RMR was measured using indirect calorimetry and predicted from the size of metabolic tissue compartments as measured by dual-energy X-ray absorptiometry (DEXA). Measured RMR was lower than DEXA-predicted RMR in AMEN (1,215 ± 31 vs. 1,327 ± 18 kcal/day, P < 0.001) but not in OV (1,284 ± 24 vs. 1,252 ± 17, P = 0.16), resulting in a lower ratio of measured to DEXA-predicted RMR in AMEN (91 ± 2%) vs. OV (103 ± 2%, P < 0.001). AMEN displayed proportionally more residual mass (P < 0.001) and less adipose tissue (P = 0.003) compared with OV. A lower ratio of measured to DXA-predicted RMR was associated with lower serum total triiodothyronine (ρ = 0.38, P < 0.001) and leptin (ρ = 0.32, P = 0.004). Our findings suggest that RMR suppression in this population is not the result of a reduced size of highly active metabolic tissue compartments but is due to metabolic and endocrine adaptations at the tissue level that are indicative of energy conservation.

  13. Low resting metabolic rate in exercise-associated amenorrhea is not due to a reduced proportion of highly active metabolic tissue compartments.

    PubMed

    Koehler, Karsten; Williams, Nancy I; Mallinson, Rebecca J; Southmayd, Emily A; Allaway, Heather C M; De Souza, Mary Jane

    2016-08-01

    Exercising women with menstrual disturbances frequently display a low resting metabolic rate (RMR) when RMR is expressed relative to body size or lean mass. However, normalizing RMR for body size or lean mass does not account for potential differences in the size of tissue compartments with varying metabolic activities. To explore whether the apparent RMR suppression in women with exercise-associated amenorrhea is a consequence of a lower proportion of highly active metabolic tissue compartments or the result of metabolic adaptations related to energy conservation at the tissue level, RMR and metabolic tissue compartments were compared among exercising women with amenorrhea (AMEN; n = 42) and exercising women with eumenorrheic, ovulatory menstrual cycles (OV; n = 37). RMR was measured using indirect calorimetry and predicted from the size of metabolic tissue compartments as measured by dual-energy X-ray absorptiometry (DEXA). Measured RMR was lower than DEXA-predicted RMR in AMEN (1,215 ± 31 vs. 1,327 ± 18 kcal/day, P < 0.001) but not in OV (1,284 ± 24 vs. 1,252 ± 17, P = 0.16), resulting in a lower ratio of measured to DEXA-predicted RMR in AMEN (91 ± 2%) vs. OV (103 ± 2%, P < 0.001). AMEN displayed proportionally more residual mass (P < 0.001) and less adipose tissue (P = 0.003) compared with OV. A lower ratio of measured to DXA-predicted RMR was associated with lower serum total triiodothyronine (ρ = 0.38, P < 0.001) and leptin (ρ = 0.32, P = 0.004). Our findings suggest that RMR suppression in this population is not the result of a reduced size of highly active metabolic tissue compartments but is due to metabolic and endocrine adaptations at the tissue level that are indicative of energy conservation. PMID:27382033

  14. The temperature response of CO2 assimilation, photochemical activities and Rubisco activation in Camelina sativa, a potential bioenergy crop with limited capacity for acclimation to heat stress.

    PubMed

    Carmo-Silva, A Elizabete; Salvucci, Michael E

    2012-11-01

    The temperature optimum of photosynthesis coincides with the average daytime temperature in a species' native environment. Moderate heat stress occurs when temperatures exceed the optimum, inhibiting photosynthesis and decreasing productivity. In the present study, the temperature response of photosynthesis and the potential for heat acclimation was evaluated for Camelina sativa, a bioenergy crop. The temperature optimum of net CO(2) assimilation rate (A) under atmospheric conditions was 30-32 °C and was only slightly higher under non-photorespiratory conditions. The activation state of Rubisco was closely correlated with A at supra-optimal temperatures, exhibiting a parallel decrease with increasing leaf temperature. At both control and elevated temperatures, the modeled response of A to intercellular CO(2) concentration was consistent with Rubisco limiting A at ambient CO(2). Rubisco activation and photochemical activities were affected by moderate heat stress at lower temperatures in camelina than in the warm-adapted species cotton and tobacco. Growth under conditions that imposed a daily interval of moderate heat stress caused a 63 % reduction in camelina seed yield. Levels of cpn60 protein were elevated under the higher growth temperature, but acclimation of photosynthesis was minimal. Inactivation of Rubisco in camelina at temperatures above 35 °C was consistent with the temperature response of Rubisco activase activity and indicated that Rubisco activase was a prime target of inhibition by moderate heat stress in camelina. That photosynthesis exhibited no acclimation to moderate heat stress will likely impact the development of camelina and other cool season Brassicaceae as sources of bioenergy in a warmer world.

  15. Sediment Microbial Enzyme Activity as an Indicator of Nutrient Limitation in the Great Rivers of the Upper Mississippi River Basin

    EPA Science Inventory

    Three conclusions are evident from our comparison of approaches for estimating nutrient limitation in these large floodplain rivers: 1) water chemistry and enzymes indicate that P-limitation is more prevalent than N-limitation; 2) the Ohio River reaches are more extensively P-lim...

  16. Slow recovery of tropical old-field rainforest regrowth and the value and limitations of active restoration.

    PubMed

    Shoo, Luke P; Freebody, Kylie; Kanowski, John; Catterall, Carla P

    2016-02-01

    There is current debate about the potential for secondary regrowth to rescue tropical forests from an otherwise inevitable cascade of biodiversity loss due to land clearing and scant evidence to test how well active restoration may accelerate recovery. We used site chronosequences to compare developmental trajectories of vegetation between self-organized (i.e., spontaneous) forest regrowth and biodiversity plantings (established for ecological restoration, with many locally native tree species at high density) in the Australian wet tropics uplands. Across 28 regrowth sites aged 1-59 years, some structural attributes reached reference rainforest levels within 40 years, whereas wood volume and most tested components of native plant species richness (classified by species' origins, family, and ecological functions) reached less than 50% of reference rainforest values. Development of native tree and shrub richness was particularly slow among species that were wind dispersed or animal dispersed with large (>10 mm) seeds. Many species with animal-dispersed seeds were from near-basal evolutionary lineages that contribute to recognized World Heritage values of the study region. Faster recovery was recorded in 25 biodiversity plantings of 1-25 years in which wood volume developed more rapidly; native woody plant species richness reached values similar to reference rainforest and was better represented across all dispersal modes; and species from near-basal plant families were better (although incompletely) represented. Plantings and regrowth showed slow recovery in species richness of vines and epiphytes and in overall resemblance to forest in species composition. Our results can inform decision making about when and where to invest in active restoration and provide strong evidence that protecting old-growth forest is crucially important for sustaining tropical biodiversity.

  17. Slow recovery of tropical old-field rainforest regrowth and the value and limitations of active restoration.

    PubMed

    Shoo, Luke P; Freebody, Kylie; Kanowski, John; Catterall, Carla P

    2016-02-01

    There is current debate about the potential for secondary regrowth to rescue tropical forests from an otherwise inevitable cascade of biodiversity loss due to land clearing and scant evidence to test how well active restoration may accelerate recovery. We used site chronosequences to compare developmental trajectories of vegetation between self-organized (i.e., spontaneous) forest regrowth and biodiversity plantings (established for ecological restoration, with many locally native tree species at high density) in the Australian wet tropics uplands. Across 28 regrowth sites aged 1-59 years, some structural attributes reached reference rainforest levels within 40 years, whereas wood volume and most tested components of native plant species richness (classified by species' origins, family, and ecological functions) reached less than 50% of reference rainforest values. Development of native tree and shrub richness was particularly slow among species that were wind dispersed or animal dispersed with large (>10 mm) seeds. Many species with animal-dispersed seeds were from near-basal evolutionary lineages that contribute to recognized World Heritage values of the study region. Faster recovery was recorded in 25 biodiversity plantings of 1-25 years in which wood volume developed more rapidly; native woody plant species richness reached values similar to reference rainforest and was better represented across all dispersal modes; and species from near-basal plant families were better (although incompletely) represented. Plantings and regrowth showed slow recovery in species richness of vines and epiphytes and in overall resemblance to forest in species composition. Our results can inform decision making about when and where to invest in active restoration and provide strong evidence that protecting old-growth forest is crucially important for sustaining tropical biodiversity. PMID:26310383

  18. Importance of penicillinase production for activity of penicillin alone or in combination with sulbactam in experimental endocarditis due to methicillin-resistant Staphylococcus aureus.

    PubMed Central

    Fantin, B; Pierre, J; Castéla-Papin, N; Saint-Julien, L; Drugeon, H; Farinotti, R; Carbon, C

    1996-01-01

    The activity of penicillin, alone and in combination with sulbactam, against a heterogeneously methicillin-resistant, penicillinase-producing clinical isolate of Staphylococcus aureus and its penicillinase-negative derivative was investigated in vitro and in a rabbit experimental endocarditis model. Penicillin was significantly more effective than vancomycin against the penicillinase-negative derivative in vivo (P < 0.001), and it sterilized 25% of the vegetations. The combination of penicillin and sulbactam exhibited an in vivo synergistic effect on the penicillinase-producing strain (P < 0.01) but did not produce any advantage over treatment with vancomycin, even when a high dose of sulbactam was used (100 mg/kg of body weight every 6 h). This combination was significantly less effective against the penicillinase-producing strain than was penicillin alone against the penicillinase-negative derivative (P < 0.03). In addition, the most resistant subpopulation of the surviving bacteria, which grew on agar containing 16 micrograms of methicillin per ml, was detected in 5 of 6 animals treated with penicillin and a high dose of sulbactam against the penicillinase-producing strain compared with only 1 of 12 animals treated with penicillin alone against the penicillinase-negative derivative (P < 0.01). We conclude that penicillin is highly effective against penicillinase-negative methicillin-resistant S. aureus and that penicillinase production, rather than methicillin resistance, appears to be the limiting factor for the activity of the penicillin-sulbactam combination against penicillinase-producing, methicillin-resistant S. aureus. PMID:8723470

  19. Diffusion Limitation of Oxygen Uptake and Nitrogenase Activity in the Root Nodules of Parasponia rigida Merr. and Perry 1

    PubMed Central

    Tjepkema, John D.; Cartica, Robert J.

    1982-01-01

    Parasponia is the first non-legume genus proven to form nitrogen-fixing root nodules induced by rhizobia. Infiltration with India ink demonstrated that intercellular air spaces are lacking in the inner layers of the nodule cortex. Oxygen must diffuse through these layers to reach the cells containing the rhizobia, and it was calculated that most of the gradient in O2 partial pressure between the atmosphere and rhizobia occurs at the inner cortex. This was confirmed by O2 microelectrode measurements which showed that the O2 partial pressure was much lower in the zone of infected cells than in the cortex. Measurements of nitrogenase activity and O2 uptake as a function of temperature and partial pressure of O2 were consistent with diffusion limitation of O2 uptake by the inner cortex. In spite of the presumed absence of leghemoglobin in nodules of Parasponia rigida Merr. and Perry, energy usage for nitrogen fixation was similar to that in legume nodules. The results demonstrate that O2 regulation in legume and Parasponia nodules is very similar and differs from O2 regulation in actionorhizal nodules. Images PMID:16662284

  20. Anaerobic treatment of activated sludge from Swedish pulp and paper mills--biogas production potential and limitations.

    PubMed

    Karlsson, Anna; Truong, Xu-Bin; Gustavsson, Jenny; Svensson, Bo H; Nilsson, Fredrik; Ejlertsson, Jörgen

    2011-10-01

    The methane potential of activated sludge from six Swedish pulp and paper mills was evaluated. The methane production potential of sludge samples ranged from 100-200 NmL CH4 g(-1) volatile solids (VS) and for four of the six sludge samples the potential exceeded 170 NmL CH4 g(-1) VS. The effects of sludge age and dewatering on the methane production potential were evaluated. The effects of enzymatic and ultrasonic pre-treatment on the digestibility of sludge were also investigated, but energy or enzyme inputs in viable ranges did not exert a detectable, positive effect. Long-term, semi-continuous trials with sludge from two of the mills were also conducted in attempts to develop stable biogas production at loading rates up to 4 g VS L(-1). Cobalt addition (0.5 mg L(-1)) was here found to positively affect the turnover of acetate. High viscosity was a problem in all the experimental reactors and this limited the organic loading rate.

  1. The Challenge of Limiting Greenhouse Gas Emissions Through Activities implemented Jointly in Developing Countries: A Brazilian Perspective

    SciTech Connect

    La Rovere, E.L.

    1998-11-01

    This paper addresses, from the Brazilian perspective, the main problems with Joint Implementation/Activities Implemented Jointly (JI/AIJ) between industrialized (Annex I) and developing (non-Annex I) countries, as defined by the United Nations Framework Convention on Climate Change (UNFCCC). Four possible GHG emissions abatement measures are presented for Brazil: forest protection, reforestation projects for carbon sequestration or charcoal manufacturing, use of ethanol produced from sugar cane as a car fuel, and electrical energy conservation through an increase in end-use efficiencies. These four case studies form the basis of a discussion regarding the validity of developing countries' concerns about JI/AIJ. Recommendations are offered for overcoming the present shortcomings of JI/AIJ in developing countries. The primary conclusion is that Annex I countries' funding of JI/AIJ projects in developing countries in return for GHG emissions credits is not the best means to implement the UNFCCC. However, JI/AIJ projects can be a productive means of preventing global climate change if combined with other measures, including GHG emissions reduction targets for all countries involved in JI/AIJ projects and limits on the percentage of industrialized countries' emissions reductions that can be met through projects in developing countries.

  2. Model Vestibular Nuclei Neurons Can Exhibit a Boosting Nonlinearity Due to an Adaptation Current Regulated by Spike-Triggered Calcium and Calcium-Activated Potassium Channels.

    PubMed

    Schneider, Adam D

    2016-01-01

    In vitro studies have previously found a class of vestibular nuclei neurons to exhibit a bidirectional afterhyperpolarization (AHP) in their membrane potential, due to calcium and calcium-activated potassium conductances. More recently in vivo studies of such vestibular neurons were found to exhibit a boosting nonlinearity in their input-output tuning curves. In this paper, a Hodgkin-Huxley (HH) type neuron model, originally developed to reproduce the in vitro AHP, is shown to produce a boosting nonlinearity similar to that seen in vivo for increased the calcium conductance. Indicative of a bifurcation, the HH model is reduced to a generalized integrate-and-fire (IF) model that preserves the bifurcation structure and boosting nonliearity. By then projecting the neuron model's phase space trajectories into 2D, the underlying geometric mechanism relating the AHP and boosting nonlinearity is revealed. Further simplifications and approximations are made to derive analytic expressions for the steady steady state firing rate as a function of bias current, μ, as well as the gain (i.e. its slope) and the position of its peak at μ = μ*. Finally, although the boosting nonlinearity has not yet been experimentally observed in vitro, testable predictions indicate how it might be found. PMID:27427914

  3. Model Vestibular Nuclei Neurons Can Exhibit a Boosting Nonlinearity Due to an Adaptation Current Regulated by Spike-Triggered Calcium and Calcium-Activated Potassium Channels

    PubMed Central

    Schneider, Adam D.

    2016-01-01

    In vitro studies have previously found a class of vestibular nuclei neurons to exhibit a bidirectional afterhyperpolarization (AHP) in their membrane potential, due to calcium and calcium-activated potassium conductances. More recently in vivo studies of such vestibular neurons were found to exhibit a boosting nonlinearity in their input-output tuning curves. In this paper, a Hodgkin-Huxley (HH) type neuron model, originally developed to reproduce the in vitro AHP, is shown to produce a boosting nonlinearity similar to that seen in vivo for increased the calcium conductance. Indicative of a bifurcation, the HH model is reduced to a generalized integrate-and-fire (IF) model that preserves the bifurcation structure and boosting nonliearity. By then projecting the neuron model’s phase space trajectories into 2D, the underlying geometric mechanism relating the AHP and boosting nonlinearity is revealed. Further simplifications and approximations are made to derive analytic expressions for the steady steady state firing rate as a function of bias current, μ, as well as the gain (i.e. its slope) and the position of its peak at μ = μ*. Finally, although the boosting nonlinearity has not yet been experimentally observed in vitro, testable predictions indicate how it might be found. PMID:27427914

  4. Classification of prefrontal activity due to mental arithmetic and music imagery using hidden Markov models and frequency domain near-infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Power, Sarah D.; Falk, Tiago H.; Chau, Tom

    2010-04-01

    Near-infrared spectroscopy (NIRS) has recently been investigated as a non-invasive brain-computer interface (BCI). In particular, previous research has shown that NIRS signals recorded from the motor cortex during left- and right-hand imagery can be distinguished, providing a basis for a two-choice NIRS-BCI. In this study, we investigated the feasibility of an alternative two-choice NIRS-BCI paradigm based on the classification of prefrontal activity due to two cognitive tasks, specifically mental arithmetic and music imagery. Deploying a dual-wavelength frequency domain near-infrared spectrometer, we interrogated nine sites around the frontopolar locations (International 10-20 System) while ten able-bodied adults performed mental arithmetic and music imagery within a synchronous shape-matching paradigm. With the 18 filtered AC signals, we created task- and subject-specific maximum likelihood classifiers using hidden Markov models. Mental arithmetic and music imagery were classified with an average accuracy of 77.2% ± 7.0 across participants, with all participants significantly exceeding chance accuracies. The results suggest the potential of a two-choice NIRS-BCI based on cognitive rather than motor tasks.

  5. The sensitivity of Cockayne's syndrome cells to DNA-damaging agents is not due to defective transcription-coupled repair of active genes.

    PubMed

    van Oosterwijk, M F; Versteeg, A; Filon, R; van Zeeland, A A; Mullenders, L H